$2\cos^2\left(x\right)-1=\cos^2\left(x\right)-\sin^2\left(x\right)$

$\left(x^4+x^3+x^2-x-1\right)\left(2x\right)$

$\int\frac{x^3+2x-1}{\left(x^2-4x+8\right)^3}dx$

$\lim_{x\to0}\left(\frac{sin\left(\sqrt{x^4+x^2}\right)}{\sqrt{x^2+9}}\right)$

$1^4-1^3-1^2+1-1$

$\int\:\frac{7x^6}{\left(x^7+1\right)^2}dx$

$1-8t^5+16t^{10}$