Question

Differentiate w.r.to $x$

$x+{\cos }^{2}x=t$

Answer 1

Differentiating wrt x

$1+2cosx(-\sin x)=\frac{dt}{dx}$

$\frac{dt}{dx}=1-2\sin x\cos x$

$\frac{dt}{dx}=1-\sin 2x$