$\lim_{x\to0}\left(\frac{cos\left(8x\right)}{x^2-1}\right)$

$\lim_{x\to\pi}\frac{\left(x-\frac{\pi}{2}\right)\sin\left(x\right)\cos^2\left(x\right)dx}{\sin^3\left(x\right)\cos^3\left(x\right)dx}$

$\left(2a+3bc\right)^3$

$\int7\sen^{4}\left(3x\right)\cos^{2}\left(3x\right)dx$

$-3x^2xy^2$

$\int5e^{5x-7}dx$

$\int y\left(y+3\right)^2dx$