$\int_{\frac{\pi}{4}}^{\frac{3\pi}{4}}\left(\frac{\cos\left(x\right)}{\sin^2\left(x\right)}\right)dx$

$xydy=\left(2y^2-3x^2\right)dx$

$\frac{d}{dy}\left(\sin\left(y\right)=\cos\left(2x\right)\right)$

$x^3-4x^2-3x+18$

$\int\sqrt{9-1\left(-2x\right)}dx$

$\frac{dy}{dx}=x^8y$

$5x^2-15x$