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Question : 176 of 180
Marks:
+1,
-0
Solution:
We have,
f(x)‌=‌⇒f′(x)‌=‌=‌For maxima or minima,
‌f′(x)=0‌⇒‌‌‌=0‌⇒‌‌log‌x=1‌⇒‌‌x=e‌‌ Now, ‌f′′(x)=‌| −⋅x2−(1−log‌x)⋅2x |
| x4 |
‌=‌‌ ‌=‌=‌∴‌‌f′′(e)‌=‌=‌<0Hence,
f(x) attains a local maxima at
x=e.
∴‌‌fmax=f(e)=‌=‌
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