$-1n^2+20n$

$\int\frac{9x}{e^{3x}}dx$

$x\left(1\:-x^2+x^3-x^5\right)\:$

$y^2-0.09$

$\sin^2\left(x\right)-\cos^2\left(x\right)\left(\csc^2\left(x\right)+\cot^2\left(x\right)\right)$

$\left(8x^4-x+3\right)\left(-x^5+6\right)$

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