$\lim_{x\to\frac{\pi}{2}}\left(sen\left(x\right)\right)^{tan\left(x\right)}$

$\frac{2}{x+4}<2$

$in\left(x^5\left(3x+7\right)^9\right)$

$-\frac{1}{3}a^2+2.\frac{1}{3}a.\frac{1}{4}b+\frac{1}{4}b^2$

$2x^2y^n\left(4y^{n+2}-1\right)$

$20n^{2}-2x-20$

$\int\sqrt{8x^2-4}dx$