#### Answer

$\frac{dy}{dx} = (1+sin x)cos (x-cos x)$

#### Work Step by Step

$\frac{dy}{du} = \frac{d(sin u)}{du} = cos u$
and,
$\frac{du}{dx} = \frac{d (x-cos x)}{dx} = 1+sin x$
So,
$\frac{dy}{dx} = \frac{dy}{du}*\frac{du}{dx}$
$\frac{dy}{dx} = cos u (1+sin x)$
$\frac{dy}{dx} = (1+sin x)cos (x-cos x)$