$\lim_{x\to1}\left(\frac{\log\left(2x-1\right)}{x^2+x-2}\right)$

$3\cos\left(x-45\right)=-1$

$\frac{d}{dx}\left(y=\left(cos\left(4x\right)^x\right)\right)$

$\int3sen^2\left(\frac{bx}{c}\right)dx$

$\int_{\frac{x}{3}}^0\sec^3\left(x\right)dx$

$-3mn-16mn+20mn$

$17+16+-1$