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

$\int\left(2-sin\frac{x}{2}\right)^2cos\frac{x}{4}dx$

$\int\left(x\cdot\cos\left(x^2-1\right)\left(\frac{3}{5}\sin\left(x^2-1\right)-1\right)^{\frac{1}{2}}\right)dx$

$\int\sec^3\left(\frac{x}{3}\right)dx$

$3x^2+48xy+21y^2$

$\lim_{n\to\infty}\left(\frac{8n+7}{8n-7}\right)^n$

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