MCQ
If $x $ tends $ 0 $ to $\pi /2 $, then the given function $f(x) = x\sin x + \cos x + {\cos ^2}x$ is
- AIncreasing
- ✓Decreasing
- CNeither increasing nor decreasing
- DNone of these
$\therefore f'(x) = \sin x + x\cos x - \sin x - 2\cos x\sin x$
$ = \cos x(x - 2\sin x)$
Hence $x \to 0$ to $\pi $, then $f'(x) < 0$
$i.e.,$ $f(x)$ is decreasing function.
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