$\frac{dy}{dx}=y^4\:$

$2\cdot x\cdot\left(-5\right)\cdot x^3$

$5\left(2x\right)^3$

$lim_{x\to0}\left(\frac{4sin\left(4x\right)}{1-cos\left(4x\right)}\right)$

$\lim\:_{y\to\:0}\left(\frac{1-\sqrt{1-4y\left(x-y\right)}}{y}\right)$

$x2-5x+2x$

$\frac{d^4}{dx^4}\left(lnx\right)$