$\sec\left(x\right)=\frac{\sec^2\left(x\right)-\tan^2\left(x\right)}{\sec\left(x\right)+\tan\left(x\right)}+\tan\left(x\right)$

$\int\frac{x^5}{\left(2-x^6\right)^2}dx$

$g^2-6g+9$

$\cos\left(x-2\pi\right)-\cos\left(2\pi\right)$

$50\cdot7.5$

$\sqrt{1+\frac{y^2}{81-y^2}}$

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