Class 12 RD Sharma Solutions – Chapter 11 Differentiation – Exercise 11.5 | Set 1
Question 1. Differentiate y = x1/x with respect to x.
Solution:
We have,
=> y = x1/x
On taking log of both the sides, we get,
=> log y = log x1/x
=> log y = (1/x) (log x)
On differentiating both sides with respect to x, we get,
=>
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Question 2. Differentiate y = xsin x with respect to x.
Solution:
We have,
=> y = xsin x
On taking log of both the sides, we get,
=> log y = log xsin x
=> log y = sin x log x
On differentiating both sides with respect to x, we get,
=>
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Question 3. Differentiate y = (1 + cos x)x with respect to x.
Solution:
We have,
=> y = (1 + cos x)x
On taking log of both the sides, we get,
=> log y = log (1 + cos x)x
=> log y = x log (1 + cos x)
On differentiating both sides with respect to x, we get,
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Question 4. Differentiate
with respect to x.
Solution:
We have,
=>
On taking log of both the sides, we get,
=> log y = log
=> log y = cos−1 x log x
On differentiating both sides with respect to x, we get,
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Question 5. Differentiate y = (log x)x with respect to x.
Solution:
We have,
=> y = (log x)x
On taking log of both the sides, we get,
=> log y = log (log x)x
=> log y = x log (log x)
On differentiating both sides with respect to x, we get,
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Question 6. Differentiate y = (log x)cos x with respect to x.
Solution:
We have,
=> y = (log x)cos x
On taking log of both the sides, we get,
=> log y = log (log x)cos x
=> log y = cos x log (log x)
On differentiating both sides with respect to x, we get,
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Question 7. Differentiate y = (sin x)cos x with respect to x.
Solution:
We have,
=> y = (sin x)cos x
On taking log of both the sides, we get,
=> log y = log (sin x)cos x
=> log y = cos x log (sin x)
On differentiating both sides with respect to x, we get,
=>
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Question 8. Differentiate y = ex log x with respect to x.
Solution:
We have,
=> y=ex log x
=> y =
=> y = xx
On taking log of both the sides, we get,
=> log y = log xx
=> log y = x log x
On differentiating both sides with respect to x, we get,
=>
=>
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Question 9. Differentiate y = (sin x)log x with respect to x.
Solution:
We have,
=> y = (sin x)log x
On taking log of both the sides, we get,
=> log y = log (sin x)log x
=> log y = log x log (sin x)
On differentiating both sides with respect to x, we get,
=>
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Question 10. Differentiate y = 10log sin x with respect to x.
Solution:
We have,
=> y = 10log sin x
On taking log of both the sides, we get,
=> log y = log 10log sin x
=> log y = log (sin x) log 10
On differentiating both sides with respect to x, we get,
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Question 11. Differentiate y = (log x)log x with respect to x.
Solution:
We have,
=> y = (log x)log x
On taking log of both the sides, we get,
=> log y = log (log x)log x
=> log y = log x log (log x)
On differentiating both sides with respect to x, we get,
=>
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Question 12. Differentiate
with respect to x.
Solution:
We have,
=>
On taking log of both the sides, we get,
=> log y = log
=> log y = 10x log 10
On differentiating both sides with respect to x, we get,
=>
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Question 13. Differentiate y = sin xx with respect to x.
Solution:
We have,
=> y = sin xx
=> sin−1 y = xx
On taking log of both the sides, we get,
=> log (sin−1 y) = log xx
=> log (sin−1 y) = x log x
On differentiating both sides with respect to x, we get,
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Question 14. Differentiate y = (sin−1x)x with respect to x.
Solution:
We have,
=> y = (sin−1x)x
On taking log of both the sides, we get,
=> log y = (sin−1x)x
=> log y = x log (sin−1x)
On differentiating both sides with respect to x, we get,
=>
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Question 15. Differentiate
with respect to x.
Solution:
We have,
=>
On taking log of both the sides, we get,
=> log y = log
=> log y = sin−1x log x
On differentiating both sides with respect to x, we get,
=>
=>
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Question 16. Differentiate
with respect to x.
Solution:
We have,
=>
On taking log of both the sides, we get,
=> log y = log
=> log y =
On differentiating both sides with respect to x, we get,
=>
=>
=>
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Question 17. Differentiate
with respect to x.
Solution:
We have,
=>
On taking log of both the sides, we get,
=> log y = log
=> log y = tan−1 x log x
On differentiating both sides with respect to x, we get,
=>
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=>
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Question 18. Differentiate the following with respect to x.
(i) y = xx √x
Solution:
We have,
=> y = xx √x
On taking log of both the sides, we get,
=> log y = log (xx √x)
=> log y = log xx + log √x
=> log y = x log x +
On differentiating both sides with respect to x, we get,
=>
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(ii) 
Solution:
We have,
=>
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On differentiating both sides with respect to x, we get,
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(iii) 
Solution:
We have,
=>
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=>
On differentiating both sides with respect to x, we get,
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(iv) y = (x cos x)x + (x sin x)1/x
Solution:
We have,
=> y=(x cos x)x + (x sin x)1/x
=>
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=>
On differentiating both sides with respect to x, we get,
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(v) 
Solution:
We have,
=>
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On differentiating both sides with respect to x, we get,
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(vi) y = esin x + (tan x)x
Solution:
We have,
=> y = esin x + (tan x)x
=>
=>
On differentiating both sides with respect to x, we get,
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(vii) y = (cos x)x + (sin x)1/x
Solution:
We have,
=> y = (cos x)x + (sin x)1/x
=>
=>
On differentiating both sides with respect to x, we get,
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(viii)
, for x > 3
Solution:
We have,
=>
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On differentiating both sides with respect to x, we get,
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Question 19. Find dy/dx when y = ex + 10x + xx.
Solution:
We have,
=> y = ex + 10x + xx
=>
=>
On differentiating both sides with respect to x, we get,
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Question 20. Find dy/dx when y = xn + nx + xx + nn.
Solution:
We have,
=> y = xn + nx + xx + nn
=>
=>
On differentiating both sides with respect to x, we get,
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