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

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

$\cos^4\left(x\right)-\cos^2\left(x\right)+\sin^2\left(x\right)=\sin^4\left(x\right)$

$\frac{dy}{dx}\left(\frac{2x+y-1}{4x+2y+5}\right)$

$\left(9a^2+5x^3\right)^2$

$-7\log\left(7-2x\right)=28$

$\int_0^t\left(e^{-2u}sin\left(3t-3u\right)\right)du$