$cos\left(3x+4x\right)$

$\left(8n+4\right).2$

$6\sin\left(\frac{\pi}{10}\right)\cos\left(\frac{\pi}{10}\right)$

$\int\frac{e^x}{x^{-1}}dx$

$\int\left(x\left(4x-30\right)^{10}\right)dx$

$\lim_{x\to0}\left(\frac{1}{\sin\left(8x\right)}\cos\left(7x\right)\right)$

$4+42$