$20x^3-36x$

$\left(0.36\right)+\:\left(-2.5\right)$

$-3256+1523$

$-2\left|-3+2\left(4-6\right)\right|$

$\int-2\cos^2\left(2x\right)dx$

$\frac{2\sin x}{2\left(1-\cos2x\right)}=\frac{1}{\sin\left(x\right)}$

$\sin\left(x\right)^2+\frac{\sin\left(x\right)\cos\left(x\right)}{\cos\left(x\right)}=0$