$6\cos^2\left(x\right)-3=3-6\sin^2\left(x\right)$

$\left(\frac{1}{2}a^3-\frac{3}{4}\right)\left(\frac{1}{4}a^3-\frac{2}{5}\right)$

$\frac{x^2-1}{2x^2-x-1}$

$\frac{3x^2y^3-5x^2y^4}{3x^2}$

$\lim_{x\to-\pi}\left(\frac{4\cos\left(x+4\right)}{\left(x+\pi\right)^2}\right)$

$\left(2x-1\right)\left(3x+12\right)$

$\sin\left(\arctan\left(0.2\right)\right)$