$\int x\cdot sen\left(x\right)\cdot\cos\left(nx\right)dx$

$\int\frac{7\sqrt{x}}{x+9}dx$

$\lim_{x\to-1}\left(\frac{x^4+3x^3-x^2+x+4}{x+1}\right)$

$\left(x^5\right)\frac{1}{1+\left(x^2\right)}$

$-2\left(y\:-\:5\right)$

$\tan^7\left(x\right)=\tan\left(x\right)$

$3x^2+\frac{7x}{4}+\frac{1}{8}$