$\left(3ab^4\right)^4$

$\int\frac{2x\ln\left(x^2+1\right)}{\left(x^2+1\right)}dx$

$\frac{\cos\left(2x\right)-\cos\left(4x\right)}{\sin\left(2x\right)+\sin\left(4x\right)}$

$\frac{1}{5}\cdot\frac{\frac{1}{4}x}{x+1}$

$\left(-y^2+3y\right)\left(3y+y^4\right)$

$\left(2x^{3}-10x^{2}+9x-10\right):\left(x-4\right)$

$\int\left(\arccos\:\left(x\right)\right)^2dx$