$\frac{\cot\left(x\right)\tan\left(x\right)}{\sec\left(x\right)}=\cos\left(x\right)$

$\int-15x^4dx$

$100x^2+20x+4$

$dx=4\cos\left(\theta\:\right)d\theta$

$\left(x^2-12x+11\right)\frac{dy}{dx}=y$

$\lim_{x\to0}\left(\frac{2x+sin\left(x\right)}{6x\:+cos\left(x\right)}\right)$

$6z^2y+3yz^2+\frac{1}{2}yz^2$