$25x^2+8xy$

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

$cotx-cotxcos^2$

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

$\left(\frac{1}{2}a+b\right)\cdot\left(\frac{1}{2}a-b\right)$

$dy=\sqrt{1-y^2}dx\frac{1}{2}$

$\frac{\pi}{12}+\left(-1\right)\pi$