$\sin\left(x\right)\cot\left(x\right)$

$\lim_{x\to0}\left(\left(7\left(sin\left(x\right)\right)^2\:\left(\tan\:\:\left(x\right)\right)^2\right)\right)$

$\lim_{x\to0}\left(\frac{1-cos\left(6x\right)}{9x^2}\right)$

$\int6.1\left(\cos\left(3x\right)^3\right)dx$

$\frac{dy}{dx}=\left(1-2x\right)y^2$

$\frac{dy}{dt}=\frac{t}{y^{2}},y\left(1\right)=1$

$15xz+5xz$