How to Integrate sin^2(x)

 

$$\begin{array}{l}HowtoSolve{\displaystyle \int {\sin }^{2}xdx}\\ {\displaystyle \int {\sin }^{2}xdx}={\displaystyle \int \frac{(1-\cos 2x)}{2}}\text{d}x\\ =\frac{1}{2}{\displaystyle \int (1-\cos 2x)dx=\frac{1}{2}(x-\frac{\sin 2x}{2})}+c\end{array}$$