# What is the Integral Test for Convergence of an Infinite Series?

If $f$ is a function such that $f \left(n\right) = {a}_{n}$, then
${\sum}_{n = 1}^{\infty} {a}_{n}$ and ${\int}_{1}^{\infty} f \left(x\right) \mathrm{dx}$ converge or diverge together.