Question

If y = sin(x) Prove that dy/dx = y cot(x)

Answer 1

$y=sin(x)\implies \cfrac{dy}{dx}=\boxed{cos(x)} \\\\[-0.35em] ~\dotfill\\\\ ycot(x)\implies \stackrel{y}{~~\begin{matrix} sin(x) \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~ }\cfrac{cos(x)}{~~\begin{matrix} sin(x) \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~ }\implies \boxed{cos(x)}$