$\lim_{x\to1}\left(\frac{4\left(x-1\right)}{\pi-4\arctan\left(x\right)}\right)$

$\left(2x^2+\frac{2}{5}y\right)^2$

$2x\le2x+1$

$\left(x+4\right)x\left(x-4\right)$

$-2+\frac{16}{2}$

$\frac{8a^5b^6}{24a^3b^2}$

$1-\sin^2\left(t\right)+\tan^2\left(t\right)-\tan^2\left(t\right)\sin^2\left(t\right)$