$\int_2^3\left(\frac{1}{1+x^2}\right)dx$

$\int_1^3\frac{1}{x^4\left(x^2-1\right)^{\frac{1}{2}}}dx$

$\int\frac{x^2-1}{\left(x+3\right)^3}dx$

$\lim_{x\to5}\left(\frac{1}{\left(x-5\right)^2}\right)$

$p\left(x\right)a\left(x\right)+r\left(x\right)$

$\int\:\frac{1}{x^2-5}dx$

$\int\frac{x^3-2x+3}{x-1}dx$