$\int_{-\infty}^{0}3xe^{x^{2}}dx$

$\int\left(x^3-x+1\right)\cos\left(x\right)dx$

$\left(0.7\right)\left(0.7\right)$

$\left(x+5\right)\left(x+2\right)+\left(x+5\right)\left(x-2\right)-2x^2$

$\:\int\:\frac{x}{x^3+100x}dx$

$\int18x\left(\sin\left(8+3x^2\right)\right)dx$

$\lim_{x\to0.01}\left(\frac{2x^2-x-1}{x-1}\right)$