$\left(x^2-2x-7\right)\left(x\right)$

$\int\left(\frac{1}{x\sqrt{1+\ln\left(x\right)}}\right)dx$

$cos^2u$

$\lim_{x\to a}\left(\frac{5x^3}{25}\right)-1000$

$8x^2+65x+63$

$\frac{x^5+243}{x+3}$

$\lim_{x\to0}\left(\frac{5-\cos\left(9x\right)1}{sin\left(7x\right)-7x}\right)$