$\lim\:_{x\to\:-\infty\:}2sin\left(\frac{tan^{-1}x}{3}\right)$

$\left(x+2\right)\left(x^3+2x^2-2x\right)=x^2+2x$

$\int\left(7x^2+4\right)e^{2x}dx$

$\lim_{x\to0}\left(x^4sin\left(\frac{1}{x}\right)+2\right)$

$\left(x^2+3y\right)-2z\left(x^2+3y\right)+2z$

$\frac{3sin^2x+4sinx+1}{sin^2+2sinx+1}$

$35\cdot2$