$\int\frac{cos\frac{x}{2}}{sen\frac{x}{2}}\:dx$

$4^2-7-\left(-7\right)^2$

$\left(3+b\right)^4$

$11-\frac{15}{x}=4+\frac{6}{x}$

$\frac{1+\sin\left(x\right)}{\sin\left(x\right).\cos\left(x\right)}=\frac{1+\sin\left(x\right)}{\cos\left(x\right)}+\frac{\cos\left(x\right)}{\sin\left(x\right)}$

$\lim_{x\to\infty}\left(\frac{sin\left(x\right)}{2tan\left(x\right)}.\left(1+tan\left(2x\right)^{\frac{1}{4}}\right)\right)$

$\int\frac{1}{\sqrt{9-64x^2}}dx$