$\left(y^2-\frac{1}{4y^2}+1\right)^2$

$\cos\left(13\right)\cos\left(12\right)-\sin\left(13\right)\sin\left(12\right)$

$4\sqrt[3]{x^2}\cdot\frac{1}{2}\cdot\sqrt[6]{x}$

$\frac{dy}{dx}=\frac{2}{5x+3}$

$3n-7+n+2$

$\frac{d}{dx}9\cos x+2$

$5x^3y^4\left(3x^2y^2-7x^{5y}\right)$