$\lim_{x\to6}\left(\sec\left(6\right)^2\right)$

$\frac{dy}{dx}=x\cdot e^{-y}$

$\left(7y^2+4\right)^2$

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

$\int\frac{6x^3}{\left(x^3+1\right)}dx$

$\left(-7x^3+6x^2-9x+9\right)+\left(4x^3+6x^2-2x-6\right)$

$9-\left(-64\right)+\left(-20\right)$