Question

Find the area bounded by the curve $y=\cos x$ between $x=0$ and $x=2\pi$

Answer 1

$A={\int }_0^{2x}\cos xdx$

$A={\left[\sin x\right]}_0^{\pi /4}A={\left[\sin x\right]}_0^{2\pi }$

$A=(\sin 2\pi -\sin 0)=0$