$81a^8-16b^{16}$

$\lim_{x\to5}\left(x^2+4x-3\right)$

$\frac{4a^3+5a}{2a-1}$

$\int_{\frac{\pi}{2}}^{\frac{3\pi}{2}}\left(-cosx\right)dx$

$\int_1^{\infty}\left(\frac{1}{1-2x^2}\right)dx$

$tanh\left(u+v\right)=\frac{tanh\left(u\right)+tanh\left(v\right)}{1+tanh\left(u\right)\:tanh\left(v\right)}$

$\int\frac{\left(2xin\left(x^2+1\right)\right)}{x^2+1}dx$