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Differentiation

Class 11th Mathematics RS Aggarwal Solution
Exercise 28a
  1. ###Common###(i) x-3(ii) cube root {x} Differentiate the following functions:…
  2. (i) {1}/{x} (ii) {1}/{ root {x} } (iii) {1}/{ cube root {x} }…
  3. (i) 3x-5(ii) {1}/{5x} (iii) 6 cube root { x^{2} } Differentiate the…
  4. (i) 6x5 + 4x3 – 3x2 + 2x – 7(ii) 5x^{-3/2} + {4}/{ root {x} } + sqrt{x} -…
  5. (i) 4x^{3} + 3.2^{x} + 6 c. root [8] { x^{-4} } + 5cotx (ii) {x}/{3} -…
  6. (i) 4cotx - {1}/{2} cosx + frac {2}/{cosx} - frac {3}/{sinx} + frac…
  7. (i) (2x + 3) (3x – 5)(ii) x(1 + x)3(iii) ( root {x} + {1}/{x} ) ( x - frac…
  8. (i) { 3x^{2} + 4x-5 }/{x} (ii) { ( x^{3} + 1 ) (x-2) }/{ x^{2} } (iii)…
  9. (i) If y = 6x5 – 4x4 – 2x2 + 5x – 9, find {dy}/{dx} at x = -1.(ii) If y =…
  10. If y = ( root {x} + {1}/{ sqrt{x} } ) , show that 2x c. {dy}/{dx} + y…
  11. If y = ( root { {x}/{a} } + sqrt { frac {a}/{x} } ) , prove that (2xy)…
  12. If y = root { {1+cos2x}/{1-cos2x} } , find {dy}/{dx} .
  13. y = { 1-tan^{2} (x/2) }/{ 1+tan^{2} (x/2) } , find {dy}/{dx}…
Exercise 28b
  1. (ax + b) Find the derivation of each of the following from the first principle:…
  2. ( ax^{2} + {b}/{x} ) Find the derivation of each of the following from the…
  3. 3x2 + 2x – 5 Find the derivation of each of the following from the first…
  4. x3 – 2x2 + x + 3 Find the derivation of each of the following from the first…
  5. x8 Find the derivation of each of the following from the first principle:…
  6. {1}/{ x^{3} } Find the derivation of each of the following from the first…
  7. {1}/{ x^{5} } Find the derivation of each of the following from the first…
  8. root {ax+b} Find the derivation of each of the following from the first…
  9. root {5x-4} Find the derivation of each of the following from the first…
  10. {1}/{ root {x+2} } Find the derivation of each of the following from the first…
  11. {1}/{ root {2x+3} } Find the derivation of each of the following from the…
  12. {1}/{ root {6x-5} } Find the derivation of each of the following from the…
  13. {1}/{ root {2-3x} } Find the derivation of each of the following from the…
  14. {2x+3}/{3x+2} Find the derivation of each of the following from the first…
  15. {5-x}/{5+x} Find the derivation of each of the following from the first…
  16. { x^{2} + 1 }/{x} , x not equal 0 Find the derivation of each of the following…
  17. root {cos3x} Find the derivation of each of the following from the first…
  18. root {secx} Find the derivation of each of the following from the first…
  19. tan2x Find the derivation of each of the following from the first principle:…
  20. sin (2x + 3) Find the derivation of each of the following from the first…
  21. tan (3x + 1) Find the derivation of each of the following from the first…
Exercise 28c
  1. X2 sin x Differentiate:
  2. ex cos x Differentiate:
  3. ex cot x Differentiate:
  4. xn cot x Differentiate:
  5. x3 sec x Differentiate:
  6. (x2 + 3x + 1) sin x Differentiate:
  7. x4 tan x Differentiate:
  8. (3x – 5) (4x2 – 3 + ex) Differentiate:
  9. (x2 – 4x + 5) (x3 – 2) Differentiate:
  10. (x2 + 2x – 3) (x2 + 7x + 5) Differentiate:
  11. (tan x + sec x) (cot x + cosec x) Differentiate:
  12. (x3 cos x – 2x tan x) Differentiate:
Exercise 28d
  1. { 2^{x} }/{x} Differentiate
  2. {logx}/{x} Differentiate
  3. { e^{x} }/{ (1+x) } Differentiate
  4. { e^{x} }/{ ( 1+x^{2} ) } Differentiate
  5. ( { 2x^{2} - 4 }/{ 3x^{2} + 7 } ) Differentiate
  6. ( { x^{2} + 3x-1 }/{x+2} ) Differentiate
  7. { ( x^{2} - 1 ) }/{ ( x^{2} + 7x+1 ) } Differentiate
  8. ( { 5x^{2} + 6x+7 }/{ 2x^{2} + 3x+4 } ) Differentiate
  9. {x}/{ ( a^{2} + x^{2} ) } Differentiate
  10. { x^{4} }/{sinx} Differentiate
  11. { root {a} + sqrt{x} }/{ sqrt{a} - sqrt{x} } Differentiate
  12. {cosx}/{logx} Differentiate
  13. {2cotx}/{ root {x} } Differentiate
  14. {sinx}/{ (1+cosx) } Differentiate
  15. ( {1+sinx}/{1-sinx} ) Differentiate
  16. ( {1-cosx}/{1+cosx} ) Differentiate
  17. ( {sinx-cosx}/{sinx+cosx} ) Differentiate
  18. ( {secx-tanx}/{secx+tanx} ) Differentiate
  19. ( { e^{x} + sinx }/{1+logx} ) Differentiate
  20. {e^{x}sinx}/{secx} Differentiate
  21. {2^{x}cotx}/{ root {x} } Differentiate
  22. { e^{x} (x-1) }/{ (x+1) } Differentiate
  23. {xtanx}/{ (secx+tanx) } Differentiate
  24. ( { ax^{2} + bx+c }/{ px^{2} + qx+r } ) Differentiate
  25. ( {sinx-xcosx}/{xsinx+cosx} ) Differentiate
  26. (i) cotx(ii) secx
Exercise 28e
  1. sin 4x Differentiate the following with respect to x:
  2. cos 5x Differentiate the following with respect to x:
  3. tan3x Differentiate the following with respect to x:
  4. cos x3 Differentiate the following with respect to x:
  5. cot2x Differentiate the following with respect to x:
  6. tan3x Differentiate the following with respect to x:
  7. tan root {x} Differentiate the following with respect to x:
  8. e^ { x^{2} } Differentiate the following with respect to x:
  9. e^{cotx} Differentiate the following with respect to x:
  10. root {sinx} Differentiate the following with respect to x:
  11. (5 + 7x)6 Differentiate the following with respect to x:
  12. (3 - 4x)5 Differentiate the following with respect to x:
  13. (3x2 - x + 1)4 Differentiate the following with respect to x:
  14. (ax2 + bx + c) Differentiate the following with respect to x:
  15. {1}/{ ( x^{2} - x+3 ) ^{3} } Differentiate the following with respect to x:…
  16. sin2 (2x + 3) Differentiate the following with respect to x:
  17. cos2(x3) Differentiate the following with respect to x:
  18. root { sinx^{3} } Differentiate the following with respect to x:…
  19. root {xsinx} Differentiate the following with respect to x:
  20. root { cotsqrt{x} } Differentiate the following with respect to x:…
  21. cos 3x sin 5x Differentiate the following with respect to x:
  22. sin x sin 2x Differentiate the following with respect to x:
  23. Differentiate w.r.t x: cos ( sinroot {ax+b} )
  24. Differentiate w.r.t x: e2x sin 3x
  25. Differentiate w.r.t x: e3x cos 2x
  26. Differentiate w.r.t x: e-5x cot 4x
  27. Differentiate w.r.t x: cos (x3 . ex)
  28. Differentiate w.r.t x: e(xsinx+cosx)
  29. Differentiate w.r.t x: { e^{x} + e^{-x} }/{ e^{x} - e^{-x} }
  30. Differentiate w.r.t x: { e^{2x} + e^{-2x} }/{ e^{2x} - e^{-2x} }…
  31. Differentiate w.r.t x: root { { 1-x^{2} }/{ 1+x^{2} } }
  32. Differentiate w.r.t x: root { { a^{2} - x^{2} }/{ a^{2} + x^{2} } }…
  33. Differentiate w.r.t x: root { {1+sinx}/{1-sinx} }
  34. Differentiate w.r.t x: root { { 1+e^{x} }/{ 1-e^{x} } }
  35. Differentiate w.r.t x: { e^{2x} + x^{3} }/{cosec2x}
  36. Find {dy}/{dx} ,When y = sinroot {sinx+cosx} Find ,When
  37. Find {dy}/{dx} ,When = ex log (sin 2x) Find ,When
  38. Find {dy}/{dx} ,When y = cos ( { 1-x^{2} }/{ 1+x^{2} } ) Find ,When…
  39. Find {dy}/{dx} ,When y = sin ( { 1+x^{2} }/{ 1-x^{2} } ) Find ,When…
  40. Find {dy}/{dx} ,When y = { sinx+x^{2} }/{cot2x} Find ,When…
  41. If y = {cosx-sinx}/{cosx+sinx} , show that {dy}/{dx} + y^{2} + 1 = 0…
  42. If y = {cosx+sinx}/{cosx-sinx} , show that {dy}/{dx} = sec^{2} ( x +…
  43. y = root { {1-x}/{1+x} } , prove that ( 1-x^{2} ) {dy}/{dx} + y = 0…
  44. y = root { {secx-tanx}/{secx+tanx} } , show that {dy}/{dx} = secx…

Exercise 28a
Question 1.

Differentiate the following functions:
(i) x-3

(ii)


Answer:

(i) x-3


Formula:-


= n


Differentiating w.r.t x,


= -3


= -3


(ii) =


Formula:-


= n


Differentiating w.r.t x,


=


=



Question 2.

Differentiate the following functions:

(i)

(ii)

(iii)


Answer:

(i) =


Formula:-


= n


Differentiating w.r.t x,


= -1


= -


(ii) =


Formula:-


= n


Differentiating w.r.t x,


=


=


(iii) =


Formula:-


= n


Differentiating w.r.t x,


=


=



Question 3.

Differentiate the following functions:

(i) 3x-5

(ii)

(iii)


Answer:

(i) 3x-5


Formula:-


= n


Differentiating with respect to x,


= 3(-5)


= -15


(ii) 1/5x =


Formula:-


= n


Differentiating with respect to x,


=


= -


(iii) =


Formula:-


= n


Differentiating with respect to x,


=


=



Question 4.

Differentiate the following functions:

(i) 6x5 + 4x3 – 3x2 + 2x – 7

(ii)

(iii) ax3 + bx2 + cx + d, where a, b, c, d are constants


Answer:

(i) 6x5 + 4x3 – 3x2 + 2x – 7


Formula:-


= n


Differentiating with respect to x,


6x5 + 4x3 – 3x2 + 2x – 730x5-1 + 12x3-1 – 6x2-1 + 2x1-1 + 0


= 30x4 + 12x2 – 6x1 + 2x


(ii)


Formula:-


= n


Differentiating with respect to x,



=


=


(iii) ax3 + bx2 + cx + d, where a, b, c, d are constants


Formula:-


= n


Differentiating with respect to x,


ax3 + bx2 + cx + d) = 3ax3-1 + 2bx2-1 + c + d×0


= 3ax2 + 2bx + c



Question 5.

Differentiate the following functions:

(i)

(ii)


Answer:

(i)


=


Formulae:


= n


- cosec2x


ax = logn(a)×ax


Differentiating with respect to x,



= 4.3x3-1 + 3.logn(2).2x + 6×- + 5 ×- cosec2x


= 12x2 + 3.logn(2).2x -3 -5 cosec2x


(ii)


=


= n


ax = logn(a)×ax


Differentiating with respect to x,



=


=



Question 6.

Differentiate the following functions:

(i)

(ii) -5 tan x + 4 tan x cos x – 3 cot x sec x + 2sec x – 13


Answer:

Formulae: -


- cosec2x


- sinx


secx tanx


- cosecx cotx


sec2x


cosx


0,k is constant


(i)


=


Differentiating with respect to x,



=


=


(ii) -5 tan x + 4 tan x cos x – 3 cot x sec x + 2sec x – 13


= -5 tan x + 4 sinx – 3 cosecx+ 2sec x – 13


Differentiating with respect to x,


-5 tan x + 4 sinx – 3 cosecx+ 2sec x – 13


= -5 sec2x + 4cosx -3(- cosecx cotx) + 2 secx tanx – 0


= -5 sec2x + 4cosx + 3 cosecx cotx + 2 secx tanx



Question 7.

Differentiate the following functions:

(i) (2x + 3) (3x – 5)

(ii) x(1 + x)3

(iii)

(iv)

(v)

(vi) (2x2 + 5x – 1) (x – 3)


Answer:

Formula:



Chain rule -



Where u and v are the functions of x.


(i) (2x + 3) (3x – 5)


Applying, Chain rule


Here, u = 2x + 3


V = 3x -5


(2x + 3) (3x – 5)


= (2x + 3)(3x1-1+0) + (3x – 5)(2x1-1+0)


= 6x + 9 + 6x -10


= 12x -1


(ii) x(1 + x)3


Applying, Chain rule


Here, u = x


V = (1 + x)3


x(1 + x)3


= x×3×(1 + x)2 + (1 + x)3(1)


= (1 + x)2(3x+x+1)


= (1 + x)2(4x+1)


(iii) = (x1/2 + x-1)(x – x-1/2 )


Applying, Chain rule


Here, u = (x1/2 + x-1)


V = (x – x-1/2 )


(x1/2 + x-1)(x – x-1/2 )


= (x1/2 + x-1)(x – x-1/2 ) + (x – x-1/2 )(x1/2 + x-1)


= (x1/2 + x-1)(1+ x-3/2) + (x – x-1/2 )(x-1/2 – x-2)


= x1/2 + x-1 + x-1 + x-5/2 + x1/2 – x-1 - x-1 + x-5/2


= x1/2 + x-5/2


(iv)


Differentiation of composite function can be done by



Here, f(g) = g2 , g(x) =


= 2g×(1 + )


= 2( (1 + )


= 2(x + - + )


= 2(x + )


(v)


Differentiation of composite function can be done by



Here, f(g) = g3 , g(x) = x2 -


= 3g2×(2x - )


= 3 (2x - )


= 3(2x3 - - + )


= 3(2x3 - + )


(vi) (2x2 + 5x – 1) (x – 3)


Applying, Chain rule


Here, u = (2x2 + 5x – 1)


V = (x – 3)


(2x2 + 5x – 1) (x – 3)


(2x2 + 5x – 1)(2x2 + 5x – 1)


= (2x2 + 5x – 1)×1 + (x – 3)(4x + 5)


= 2x2 + 5x – 1 + 4x2 -7x -15


= 6x2 -2x -16



Question 8.

Differentiate the following functions:

(i)

(ii)

(iii)

(iv)

(v)

(vi)


Answer:

Formula:



(i)


Applying, quotient rule



=


=


=


(ii)


Applying, quotient rule



=


=


=


=


=


(iii)


Applying, quotient rule



=


=


=


=


(iv)


Applying, quotient rule



=


=


=


=


=


=


(v)


Applying, quotient rule



=


=


(vi)


Applying, quotient rule



=


=


=



Question 9.

Differentiate the following functions:

(i) If y = 6x5 – 4x4 – 2x2 + 5x – 9, find at x = -1.

(ii) If y = (sin x + tan x), find at .

(iii) If , find at .


Answer:

Formulae:


= n


- cosec2x


- cosecx cotx


sec2x


cosx


(i) If y = 6x5 – 4x4 – 2x2 + 5x – 9, find at x = -1.


Differentiating with respect to x,


6x5 - 4x4 – 2x2 + 5x – 9


30x4 -16x3 – 4x + 5



(x= -1 = 30(-1)4 -16(-1)3 – 4(-1) + 5


= 30+16+4+5


= 55


(ii) If y = (sin x + tan x), find at .


Differentiating with respect to x,


sinx + tanx) = cos x + sec2 x


Substituting


x = π/3 = cos + sec2


= + 4


=


(iii) If , find at .


Differentiating with respect to x,


2cosec x-3cot x) = 2(- cosecx cotx) – 3(- cosec2x)


Substituting


x = π/4 = 2(- cosec cot) – 3(- cosec2)


= - 2× + 3×2


= 6 - 2×



Question 10.

If , show that .


Answer:

To show:


Differentiating with respect to x


= =


Now,


LHS =


LHS = )


LHS = +


LHS = 2


∴ LHS = RHS



Question 11.

If , prove that .


Answer:

To prove:.


Differentiating y with respect to x


=


Now,


LHS =


LHS =


LHS = ()()


LHS =


∴ LHS = RHS



Question 12.

If , find .


Answer:


Formula:


Using double angle formula:


2cos2x – 1


= 1 – 2 sin2 x


∴1 + cos 2 x = 2cos2x


1 - cos 2 x = 2sin2x



=


= cotx


Differentiating y with respect to x


=


- cosec2 x



Question 13.

, find


Answer:

Formula:


Using Half angle formula,


cos x =


∴y = cos x


Differentiating y with respect to x






Exercise 28b
Question 1.

Find the derivation of each of the following from the first principle:

(ax + b)


Answer:

Let f(x) = ax + b

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)


f(x) = ax + b


f(x + h) = a(x + h) + b


= ax + ah + b


Putting values in (i), we get






f’(x) = a


Hence, f’(x) = a



Question 2.

Find the derivation of each of the following from the first principle:




Answer:


We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get









Taking ‘h’ common from both the numerator and denominator, we get



Putting h = 0, we get




Hence,



Question 3.

Find the derivation of each of the following from the first principle:

3x2 + 2x – 5


Answer:

Let f(x) = 3x2 + 2x – 5

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)


f(x) = 3x2 + 2x – 5


f(x + h) = 3(x + h)2 + 2(x + h) – 5


= 3(x2 + h2 + 2xh) + 2x + 2h – 5


[∵(a + b)2 = a2 + b2 + 2ab]


= 3x2 + 3h2 + 6xh + 2x + 2h – 5


Putting values in (i), we get






Putting h = 0, we get


f’(x) = 3(0) + 6x + 2


= 6x + 2


Hence, f’(x) = 6x + 2



Question 4.

Find the derivation of each of the following from the first principle:

x3 – 2x2 + x + 3


Answer:

Let f(x) = x3 – 2x2 + x + 3

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)


f(x) = x3 – 2x2 + x + 3


f(x + h) = (x + h)3 – 2(x + h)2 + (x + h) + 3


Putting values in (i), we get





Using the identities:


(a + b)3 = a3 + b3 + 3ab2 + 3a2b


(a + b)2 = a2 + b2 + 2ab






Putting h = 0, we get


f’(x) = (0)2 + 2x(0) + 3x2 – 2(0) – 4x + 1


= 3x2 – 4x + 1


Hence, f’(x) = 3x2 – 4x + 1



Question 5.

Find the derivation of each of the following from the first principle:

x8


Answer:

Let f(x) = x8

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)


f(x) = x8


f(x + h) = (x + h)8


Putting values in (i), we get




[Add and subtract x in denominator]



= 8x8-1


= 8x7


Hence, f’(x) = 8x7



Question 6.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get




[Add and subtract x in denominator]



= (-3)x-3-1


= -3x-4



Hence,



Question 7.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get




[Add and subtract x in denominator]



= (-5)x-5-1


= -5x-6



Hence,



Question 8.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)





Putting values in (i), we get



Now rationalizing the numerator by multiplying and divide by the conjugate of



Using the formula:


(a + b)(a – b) = (a2 – b2)






Putting h = 0, we get





Hence,



Question 9.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)





Putting values in (i), we get



Now rationalizing the numerator by multiplying and divide by the conjugate of



Using the formula:


(a + b)(a – b) = (a2 – b2)






Putting h = 0, we get





Hence,



Question 10.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get




Now rationalizing the numerator by multiplying and divide by the conjugate of



Using the formula:


(a + b)(a – b) = (a2 – b2)






Putting h = 0, we get





Hence,



Question 11.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get




Now rationalizing the numerator by multiplying and divide by the conjugate of



Using the formula:


(a + b)(a – b) = (a2 – b2)






Putting h = 0, we get






Hence,



Question 12.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get




Now rationalizing the numerator by multiplying and divide by the conjugate of



Using the formula:


(a + b)(a – b) = (a2 – b2)






Putting h = 0, we get






Hence,



Question 13.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get




Now rationalizing the numerator by multiplying and divide by the conjugate of



Using the formula:


(a + b)(a – b) = (a2 – b2)






Putting h = 0, we get





Hence,



Question 14.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get








Putting h = 0, we get





Hence,



Question 15.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get








Putting h = 0, we get





Hence,



Question 16.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get








Putting h = 0, we get




Hence,



Question 17.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)





Putting values in (i), we get



Now rationalizing the numerator by multiplying and divide by the conjugate of



Using the formula:


(a + b)(a – b) = (a2 – b2)




Using the formula:










Putting h = 0, we get





Hence,



Question 18.

Find the derivation of each of the following from the first principle:




Answer:

Let

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)




Putting values in (i), we get



Now rationalizing the numerator by multiplying and divide by the conjugate of



Using the formula:


(a + b)(a – b) = (a2 – b2)







Using the formula:










Putting h = 0, we get








Hence,



Question 19.

Find the derivation of each of the following from the first principle:

tan2x


Answer:

Let f(x) = tan2x

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)


f(x) = tan2x


f(x + h) = tan2(x + h)


Putting values in (i), we get




Using:






[∵ sin A cos B – sin B cos A = sin(A – B)


& sin A cos B + sin B cos A = sin(A + B)]






Putting h = 0, we get





[∵ sin2x = 2sinxcosx]



= 2tanx sec2x



Hence, f’(x) = 2tanx sec2x



Question 20.

Find the derivation of each of the following from the first principle:

sin (2x + 3)


Answer:

Let f(x) = sin (2x + 3)

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)


f(x) = sin (2x + 3)


f(x + h) = sin [2(x + h) + 3]


Putting values in (i), we get



Using the formula:










Putting h = 0, we get


= 2cos(2x + 0 + 3)


= 2cos(2x + 3)


Hence, f’(x) = 2cos (2x + 3)



Question 21.

Find the derivation of each of the following from the first principle:

tan (3x + 1)


Answer:

Let f(x) = tan (3x + 1)

We need to find the derivative of f(x) i.e. f’(x)


We know that,


…(i)


f(x) = tan (3x + 1)


f(x + h) = tan [3(x + h) + 1]


Putting values in (i), we get



Using the formula:










Putting h = 0, we get





= 3sec2(3x+ 1)


Hence, f’(x) = 3sec2(3x+ 1)




Exercise 28c
Question 1.

Differentiate:

X2 sin x


Answer:

To find: Differentiation of x2 sin x


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


Let us take u = x2 and v = sinx




Putting the above obtained values in the formula:-


(uv)′ = u′v + uv′


(x2 sin x)’ = 2x × sinx + x2 × cosx


= 2xsinx + x2cosx


Ans) 2xsinx + x2cosx



Question 2.

Differentiate:

ex cos x


Answer:

To find: Differentiation of ex cos x


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


Let us take u = ex and v = cosx




Putting the above obtained values in the formula:-


(uv)′ = u′v + uv′


(ex cosx)’ = ex× cosx + ex× -sinx


= excosx - exsinx


= ex (cosx - sinx)


Ans) ex (cosx - sinx)



Question 3.

Differentiate:

ex cot x


Answer:

To find: Differentiation of ex cot x


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


Let us take u = ex and v = cotx




Putting the above obtained values in the formula:-


(uv)′ = u′v + uv′


(ex cotx)’ = ex× cotx + ex× -cosec2x


= excotx - excosec2x


= ex (cotx - cosec2x)


Ans) ex (cotx - cosec2x)



Question 4.

Differentiate:

xn cot x


Answer:

To find: Differentiation of xn cot x


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


Let us take u = xn and v = cotx




Putting the above obtained values in the formula :-


(uv)′ = u′v + uv′


(xn cotx)’ = nxn-1× cotx + xn× -cosec2x


= nxn-1cotx - xncosec2x


= xn (nx-1cotx - cosec2x)


Ans) xn (nx-1cotx - cosec2x)



Question 5.

Differentiate:

x3 sec x


Answer:

To find: Differentiation of x3 sec x


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


Let us take u = x3 and v = sec x




Putting the above obtained values in the formula :-


(uv)′ = u′v + uv′


(x3 sec x)’ = 3x2× secx + x3× secx tanx


= 3x2secx + x3secx tanx


= x2secx(3 + x tanx)


Ans) x2secx(3 + x tanx)



Question 6.

Differentiate:

(x2 + 3x + 1) sin x


Answer:

To find: Differentiation of (x2 + 3x + 1) sin x


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


Let us take u = x2 + 3x + 1 and v = sin x




Putting the above obtained values in the formula :-


(uv)′ = u′v + uv′


[(x2 + 3x + 1) sin x]’ = (2x + 3) × sinx + (x2 + 3x + 1) × cosx


= sinx (2x + 3) + cosx (x2 + 3x + 1)


Ans) (2x + 3) sinx + (x2 + 3x + 1) cosx



Question 7.

Differentiate:

x4 tan x


Answer:

To find: Differentiation of x4 tan x


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


Let us take u = x4 and v = tan x




Putting the above obtained values in the formula:-


(uv)′ = u′v + uv′


(x4 tan x)’ = 4x3× tanx + x4× sec2x


= 4x3tanx + x4sec2x


= x3 (4tanx + xsec2x)


Ans) x3 (4tanx + xsec2x)



Question 8.

Differentiate:

(3x – 5) (4x2 – 3 + ex)


Answer:

To find: Differentiation of (3x – 5) (4x2 – 3 + ex)


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


Let us take u = (3x – 5) and v = (4x2 – 3 + ex)




Putting the above obtained values in the formula :-


(uv)′ = u′v + uv′


[(3x – 5)(4x2 – 3 + ex)]’ = 3×(4x2 – 3 + ex) + (3x – 5)×(8x + ex)


= 12x2 – 9 + 3ex+ 24x2 + 3xex – 40x - 5ex


= 36x2 + x(3ex – 40) – 9 - 2ex


Ans) 36x2 + x(3ex – 40) – 9 - 2ex



Question 9.

Differentiate:

(x2 – 4x + 5) (x3 – 2)


Answer:

To find: Differentiation of (x2 – 4x + 5) (x3 – 2)


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


Let us take u = (x2 – 4x + 5) and v = (x3 – 2)




Putting the above obtained values in the formula:-


(uv)′ = u′v + uv′


[(x2 – 4x + 5) (x3 – 2)]’ = (2x – 4)×(x3 – 2) + (x2 – 4x + 5)×(3x2)


= 2x4 – 4x - 4x3 + 8 + 3x4 – 12x3 + 15x2


= 5x4 - 16x3 + 15x2 – 4x + 8


Ans) 5x4 - 16x3 + 15x2 – 4x + 8



Question 10.

Differentiate:

(x2 + 2x – 3) (x2 + 7x + 5)


Answer:

To find: Differentiation of (x2 + 2x – 3) (x2 + 7x + 5)


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


Let us take u = (x2 + 2x – 3) and v = (x2 + 7x + 5)




Putting the above obtained values in the formula :-


(uv)′ = u′v + uv′


[(x2 + 2x – 3) (x2 + 7x + 5)]’


= (2x + 2) × (x2 + 7x + 5) + (x2 + 2x – 3) × (2x + 7)


= 2x3 + 14x2 + 10x + 2x2 + 14x + 10 + 2x3 + 7x2 + 4x2 + 14x – 6x – 21


= 4x3 + 27x2 + 32x – 11


Ans) 4x3 + 27x2 + 32x – 11



Question 11.

Differentiate:

(tan x + sec x) (cot x + cosec x)


Answer:

To find: Differentiation of (tan x + sec x) (cot x + cosec x)


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


(iv)


(v)


Let us take u = (tan x + sec x) and v = (cot x + cosec x)





Putting the above obtained values in the formula:-


(uv)′ = u′v + uv′


[(tan x + sec x) (cot x + cosec x)]’


= [secx (secx + tanx)] × [(cot x + cosec x)] + [(tan x + sec x)] × [-cosecx (cosecx + cotx)]


= (secx +tanx) [secx(cotx + cosecx) - cosecx(cosecx + cotx)]


= (secx + tanx) (secx – cosecx) (cotx + cosecx)


Ans) (secx + tanx) (secx – cosecx) (cotx + cosecx)



Question 12.

Differentiate:

(x3 cos x – 2x tan x)


Answer:

To find: Differentiation of (x3 cos x – 2x tan x)


Formula used: (i) (uv)′ = u′v + uv′ (Leibnitz or product rule)


(ii)


(iii)


(iv)


(v)


Here we have two function (x3 cos x) and (2x tan x)


We have two differentiate them separately


Let us assume g(x) = (x3 cos x)


And h(x) = (2x tan x)


Therefore, f(x) = g(x) – h(x)


⇒ f’(x) = g’(x) – h’(x) … (i)


Applying product rule on g(x)


Let us take u = x3 and v = cos x




Putting the above obtained values in the formula:-


(uv)′ = u′v + uv′


[x3 cosx]’ = 3x2 × cosx + x3 × -sinx


= 3x2cosx - x3sinx


= x2 (3cosx – x sinx)


g’(x) = x2 (3cosx – x sinx)


Applying product rule on h(x)


Let us take u = 2x and v = tan x




Putting the above obtained values in the formula:-


(uv)′ = u′v + uv′


[2x tan x]’ = 2x log2× tanx + 2x × sec2x


= 2x (log2tanx + sec2x)


h’(x) = 2x (log2tanx + sec2x)


Putting the above obtained values in eqn. (i)


f’(x) = x2 (3cosx – x sinx) - 2x (log2tanx + sec2x)


Ans) x2 (3cosx – x sinx) - 2x (log2tanx + sec2x)




Exercise 28d
Question 1.

Differentiate


Answer:




Let us take u = 2x and v = x




Putting the above obtained values in the formula:-









Question 2.

Differentiate




Answer:




Let us take u = logx and v = x




Putting the above obtained values in the formula:-









Question 3.

Differentiate




Answer:




Let us take u = ex and v = (1+x)




Putting the above obtained values in the formula:-









Question 4.

Differentiate




Answer:






Let us take u = ex and v = (1+x2)




Putting the above obtained values in the formula:-









Question 5.

Differentiate




Answer:




Let us take u = (2x2 – 4) and v = (3x2 + 7)




Putting the above obtained values in the formula:-









Question 6.

Differentiate




Answer:




Let us take u = (x2 + 3x – 1) and v = (x + 2)




Putting the above obtained values in the formula:-









Question 7.

Differentiate




Answer:




Let us take u = (x2 – 1) and v = (x2 + 7x + 1)




Putting the above obtained values in the formula:-









Question 8.

Differentiate




Answer:




Let us take u = (5x2 + 6x + 7) and v = (2x2 + 3x + 4)




Putting the above obtained values in the formula:-










Question 9.

Differentiate




Answer:




Let us take u = (x) and v = (a2 + x2)




Putting the above obtained values in the formula:-









Question 10.

Differentiate




Answer:





Let us take u = (x4) and v = (sinx)




Putting the above obtained values in the formula:-








Question 11.

Differentiate




Answer:




Let us take u = and v =




Putting the above obtained values in the formula:-









Question 12.

Differentiate




Answer:





Let us take u = (cosx) and v = (logx)




Putting the above obtained values in the formula:-








Question 13.

Differentiate




Answer:





Let us take u = (2cotx) and v =




Putting the above obtained values in the formula:-








Question 14.

Differentiate




Answer:





Let us take u = (sinx) and v = (1 + cosx)




Putting the above obtained values in the formula:-










Question 15.

Differentiate




Answer:




Let us take u = (1 + sinx) and v = (1 - sinx)




Putting the above obtained values in the formula:-









Question 16.

Differentiate




Answer:




Let us take u = (1 - cosx) and v = (1 + cosx)




Putting the above obtained values in the formula:-









Question 17.

Differentiate




Answer:





Let us take u = (sinx - cosx) and v = (sinx + cosx)




Putting the above obtained values in the formula:-











Question 18.

Differentiate




Answer:





Let us take u = (secx - tanx) and v = (secx + tanx)




Putting the above obtained values in the formula:-












Question 19.

Differentiate




Answer:






Let us take u = () and v = ()




Putting the above obtained values in the formula:-








Question 20.

Differentiate




Answer:






(v) (uv)′ = u′v + uv′ (Leibnitz or product rule)


Let us take u = () and v = ()



Applying Product rule


(gh)′ = g′h + gh′


Taking g = ex and h = sinx


= exsinx + excosx


u’ = exsinx + excosx



Putting the above obtained values in the formula:-















Question 21.

Differentiate




Answer:






(v) (uv)′ = u′v + uv′ (Leibnitz or product rule)


Let us take u = () and v = ()



Applying Product rule


(gh)′ = g′h + gh′


Taking g = and h =


= +


u’ = -


u’ =



Putting the above obtained values in the formula:-











Question 22.

Differentiate




Answer:





(iv) (uv)′ = u′v + uv′ (Leibnitz or product rule)


Let us take u = ex(x-1) and v = (x+1)



Applying Product rule


(gh)′ = g′h + gh′


Taking g = and h = x – 1


[ex(x-1)]’ = ex(x-1) + ex (1)


= ex(x-1) + ex


u’ = exx



Putting the above obtained values in the formula:-









Question 23.

Differentiate




Answer:






(iv) (uv)′ = u′v + uv′ (Leibnitz or product rule)


Let us take u = (x tanx) and v = (secx + tanx)



Applying Product rule for finding u’


(gh)′ = g′h + gh′


Taking g = xand h = tanx


[]’ = (1) (tanx) + x (sec2x)


= tanx + xsec2x


u’ = tanx + xsec2x




Putting the above obtained values in the formula:-









Question 24.

Differentiate




Answer:




Let us take u = () and v = ()




Putting the above obtained values in the formula:-








Question 25.

Differentiate




Answer:





(iv) (uv)′ = u′v + uv′ (Leibnitz or product rule)


Let us take u = () and v = ()



Applying Product rule for finding the term xcosx in u’


(gh)′ = g′h + gh′


Taking g = xand h = cosx


[]’ = (1) (cosx) + x (-sinx)


[]’ = cosx – x sinx


Applying the above obtained value for finding u’


u’ = cosx – (cosx – x sinx)


u’ = x sinx



Applying Product rule for finding the term xsinx in v’


(gh)′ = g′h + gh′


Taking g = xand h = sinx


[]’ = (1) (sinx) + x (cosx)


[]’ = sinx + x cosx


Applying the above obtained value for finding v’


v’ = sinx + x cosx - sinx


v’ = x cosx


Putting the above obtained values in the formula:-










Question 26.

(i) cotx

(ii) secx


Answer:






Let us take u = cosx and v = sinx


u’ = (cosx)’ = -sinx


v’ = (sinx)’ = cosx


Putting the above obtained values in the formula:-









Ans).


(ii)





Let us take u = 1 and v = cosx


u’ = (1)’ = 0


v’ = (cosx)’ = -sinx


Putting the above obtained values in the formula:-







Ans).




Exercise 28e
Question 1.

Differentiate the following with respect to x:

sin 4x


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (sin nu) = cos (nu)(nu)


Let us take y = sin 4x.


So, by using the above formula, we have


(sin4x) = cos (4x) (4x) = 4cos4x.


Differentiation of y = sin 4x is 4cos4x



Question 2.

Differentiate the following with respect to x:

cos 5x


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (cos nu) = - sin (nu)(nu).


Let us take y = cos5x.


So, by using the above formula, we have


(cos5x) = - sin(5x) (5x) = - 5sin5x.


Differentiation of y = cos 5x is - 5sin5x



Question 3.

Differentiate the following with respect to x:

tan3x


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (tan nu) = sec2 (nu).(nu).


Let us take y = tan3x


So, by using the above formula, we have


tan3x = sec2(3x) (3x) = 3sec2(3x)


Differentiation of y = tan3x is 3sec2(3x)



Question 4.

Differentiate the following with respect to x:

cos x3


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (cos nu) = - sin nu(nu) and = nxn - 1


Let us take y = cos x3


So, by using the above formula, we have


cos x3 = - sin(x3)(x3) = - 3x2 sin(x3)


Differentiation of y = cos x3 is - 3x2 sin(x3)



Question 5.

Differentiate the following with respect to x:

cot2x


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (cota nu) = acota - 1(nu) (cot nu) (nu) and = nxn - 1


Let us take y = cot2x


So, by using the above formula, we have


cot2x = 2cot(x) = - 2cotx (cosec2x).


Differentiation of y = cot2x is - 2cotx (cosec2x)



Question 6.

Differentiate the following with respect to x:

tan3x


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (tananu) = atana - 1nu and = nxn - 1


Let us take y = tan3x


So, by using the above formula, we have


tan3x = 3tan2(x) = 3tan2x (sec2x).


Differentiation of y = tan3x is 3tan2x (sec2x)



Question 7.

Differentiate the following with respect to x:

tan


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (tan ) = sec2() (nu).


Let us take y = tan


So, by using the above formula, we have


tan = sec2() ()(x). = .


Differentiation of y = tan is .



Question 8.

Differentiate the following with respect to x:




Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: () = () and = nxn - 1


Let us take y =


So, by using the above formula, we have


= ()


Differentiation of y = is



Question 9.

Differentiate the following with respect to x:




Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: () = and = nxn - 1


Let us take y =


So, by using the above formula, we have


= = - cosec2x.


Differentiation of y = is - cosec2x



Question 10.

Differentiate the following with respect to x:




Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: () = ()(nu) and = nxn - 1


Let us take y =


So, by using the above formula, we have


= ()(x) = cosx


Differentiation of y = is cosx



Question 11.

Differentiate the following with respect to x:

(5 + 7x)6


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (yn) = nyn - 1


Let us take y = (5 + 7x)6


So, by using the above formula, we have


(5 + 7x)6 = 6(5 + 7x)5(5 + 7x) = 6(5 + 7x)57 = 42(5 + 7x)5


Differentiation of y = (5 + 7x)6 is 42(5 + 7x)5



Question 12.

Differentiate the following with respect to x:

(3 - 4x)5


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (yn) = nyn - 1


Let us take y= (3 - 4x)5


So, by using the above formula, we have


(3 - 4x)5 = 4(3 - 4x)5(3 - 4x)= 4(3 - 4x)5( - 4) = - 16(3 - 4x)5


Differentiation of y = (3 - 4x)5is - 16(3 - 4x)5



Question 13.

Differentiate the following with respect to x:

(3x2 - x + 1)4


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (yn) = nyn - 1


Let us take y= (3x2 - x + 1)4


So, by using the above formula, we have


(3x2 - x + 1)4 = 4(3x2 - x + 1)3(3x2 - x + 1) = 4(3x2 - x + 1)3(36x - 1) = 4(3x2 - x + 1)3(6x - 1)


Differentiation of y = (3x2 - x + 1)4 is 4(3x2 - x + 1)3(6x - 1)



Question 14.

Differentiate the following with respect to x:

(ax2 + bx + c)


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (yn) = nyn - 1


Let us take y= (ax2 + bx + c)


So, by using the above formula, we have


(ax2 + bx + c) = 2ax + b


Differentiation of y = (ax2 + bx + c) is 2ax + b



Question 15.

Differentiate the following with respect to x:




Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (yn) = nyn - 1


Let us take y= = (x2 - x + 3) - 3


So, by using the above formula, we have


(x2 - x + 3) - 3 = - 3(x2 - x + 3) - 4(2x - 1) = - 3 (2x - 1)


Differentiation of y = (x2 - x + 3) - 3 is



Question 16.

Differentiate the following with respect to x:

sin2 (2x + 3)


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: sin2 (ax + b) = 2 sin (ax + b)sin(ax + b)(ax + b)


Let us take y = sin2 (2x + 3)


So, by using above formula, we have


sin2 (2x + 3) = 2 sin (2x + 3)sin(2x + 3)(2x + 3) = 4sin(2x + 3)cos(2x + 3).


Differentiation of y = sin2 (2x + 3)is 4sin(2x + 3)cos(2x + 3)



Question 17.

Differentiate the following with respect to x:

cos2(x3)


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: (cosa nu) = acosa - 1nu (cos nu) (nu)


Let us take y = cos2(x3)


So, by using the above formula, we have


cos2(x3) = 2 cosx3 ( - sin (x3))3x2 = - 6x2 cos(x3)sin x3


Differentiation of y = cos2(x3) is - 6x2 cos(x3)sin x3



Question 18.

Differentiate the following with respect to x:




Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: () = ()(ua)


Let us take y =


So, by using the above formula, we have


= ()(x3) = ()3x2 =


Differentiation of y = is



Question 19.

Differentiate the following with respect to x:




Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: () = (u)


Let us take y =


So, by using the above formula, we have


= () = =


Differentiation of y = is



Question 20.

Differentiate the following with respect to x:




Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Formula used: () = (). ()


Let us take y =


So, by using the above formula, we have


= cot


Differentiation of y = is



Question 21.

Differentiate the following with respect to x:

cos 3x sin 5x


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Let us take y = cos 3x sin 5x


So, by using the above formula, we have


sin5 ( - 3sin 3) + cos 3(5cos 5) = 5cos (3 cos (5) - 3 sin () 3sin (3)


Differentiation of y = cos 3x sin 5x is 5cos (3 cos (5) - 3 sin () 3sin (3)



Question 22.

Differentiate the following with respect to x:

sin x sin 2x


Answer:

To Find: Differentiation


NOTE : When 2 functions are in the product then we used product rule i.e


Let us take y = sin x sin 2x


So, by using the above formula, we have


sin (2cos 2) + sin (sin) = 2sin)cos 2 + sin (sin)


Differentiation of y = sin x sin 2x is 2sin)cos 2 + sin (sin)



Question 23.

Differentiate w.r.t x:


Answer:

Let y = cos(sin ) , z = sin and w =


Formula :



According to the chain rule of differentiation






Question 24.

Differentiate w.r.t x: e2x sin 3x


Answer:

Let y = e2x sin 3x , z = e2x and w = sin 3x


Formula :


According to product rule of differentiation






Question 25.

Differentiate w.r.t x: e3x cos 2x


Answer:

Let y = e3x cos 2x , z = e3x and w = cos 2x


Formula :


According to the product rule of differentiation






Question 26.

Differentiate w.r.t x: e-5x cot 4x


Answer:

Let y = e-5x cot 4x , z = e-5x and w = cot 4x


Formula :


According to the product rule of differentiation






Question 27.

Differentiate w.r.t x: cos (x3 . ex)


Answer:

Let y = cos (x3 . ex) , z = x3 . ex , m = ex and w = x3


Formula :


According to the product rule of differentiation





According to the chain rule of differentiation





Question 28.

Differentiate w.r.t x: e(xsinx+cosx)


Answer:

Let y = e(xsinx+cosx) , z = x sin x+ cos x, m = x and w = sin x


Formula :


According to the product rule of differentiation




= x cosx


According to the chain rule of differentiation





Question 29.

Differentiate w.r.t x:


Answer:

Let y = , u = , v =


Formula :


According to the quotient rule of differentiation


If y =






( a2 – b2 = (a - b)(a + b) )





Question 30.

Differentiate w.r.t x:


Answer:

Let y = , u = , v =


Formula :


According to the quotient rule of differentiation


If y =






( a2 – b2 = (a - b)(a + b)





Question 31.

Differentiate w.r.t x:


Answer:

Let y = , u =, v = , z=


Formula :


According to the quotient rule of differentiation


If z =






According to chain rule of differentiation



=


=


=



Question 32.

Differentiate w.r.t x:


Answer:

Let y = , u =, v = , z=


Formula :


According to the quotient rule of differentiation


If z =






According to the chain rule of differentiation



=


=


=



Question 33.

Differentiate w.r.t x:


Answer:

Let y = , u =1+sin x, v = 1 – sin x , z=


Formula :


According to the quotient rule of differentiation


If z =






According to the chain rule of differentiation



=


=


=



Question 34.

Differentiate w.r.t x:


Answer:

Let y = , u = , v = , z=


Formula :


According to the quotient rule of differentiation


If z =






According to chain rule of differentiation



=


=


=



Question 35.

Differentiate w.r.t x:


Answer:

Let y = , u = , v =


Formula:


According to the quotient rule of differentiation


If y =








=




Question 36.

Find ,When


Answer:

Let y = sin( ) , z =


Formula :



According to the chain rule of differentiation






Question 37.

Find ,When = ex log (sin 2x)


Answer:

Let y = ex log (sin 2x) , z = ex and w = log (sin 2x)


Formula :


According to the product rule of differentiation







Question 38.

Find ,When


Answer:

Let y = cos ( ) , u =, v = , z=


Formula :


According to the quotient rule of differentiation


If z =






According to the chain rule of differentiation



=


=



Question 39.

Find ,When




Answer:

Let y = sin ( ) , u =, v = , z=


Formula :


According to the quotient rule of differentiation


If z =






According to the chain rule of differentiation



=



Question 40.

Find ,When




Answer:

Let y = , u = , v =


Formula:


According to the quotient rule of differentiation


If y =








=



Question 41.

If , show that


Answer:

Let , , u =, v =


Formula:


According to the quotient rule of differentiation


If y =






( )



HENCE PROVED.



Question 42.

If , show that .


Answer:

Let , , u =, v =


Formula:


According to the quotient rule of differentiation


If y =










[ cos a cos b - sin a sin b = cos (a + b)]


=


HENCE PROVED.



Question 43.

, prove that


Answer:

Let y = , u =, v = , z=


Formula :


According to quotient rule of differentiation


If z =






According to the chain rule of differentiation



=


=


=


(Muliplying and dividing by 1-x )


=


=


Therefore



HENCE PROVED



Question 44.

, show that


Answer:


y =


u =1-sin x, v = 1 + sin x , z=


Formula :


According to quotient rule of differentiation


If z =






According to the chain rule of differentiation



=


=


=


( Multiplying and dividing by )


=


=


=


=


=


=


=


=


=


=


HENCE PROVED