Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. If $ f(x) = kx - sin \,x $ is monotonically increasing, then

MHT CETMHT CET 2007

Solution:

Since, $\,\,\, f(x)=k x-\sin x $ is monotonically increasing for all $x \in R$. Therefore,
$f'(x)>0$ for all $x \in R$
$\therefore \,\,\, f'(0)>0$
$\Rightarrow \,\, k-\cos 0 >0 $
$\Rightarrow \,\, k>1$