$\frac{1}{\cos\left(x\right)\cdot\csc\left(x\right)}=\tan\left(x\right)$

$\left(4a^2-1\right)^2$

$\left(\frac{x^4}{2}\right)^4$

$\lim_{x\to\infty}\left(\frac{x^{7x}}{\left(x+1\right)^{7x+7}}\right)$

$\frac{dy}{dx}=3x^3+x^2-x+7$

$4x^5y-20x^4y^2-24x^3y^2+28x^3y^2$

$\frac{d}{dx}\frac{\left(2x^3+1\right)}{x^2}e^{x^4}$