# How do you integrate int pisinpix dx?

Dec 6, 2016

Using $u$-substitution, we will find a value in the function whose derivative will appear in the integrand.

Thus, we will let:

$u = \pi x$
$\mathrm{du} = \pi \mathrm{dx}$

So, if we plug it back in:

$= \int \sin \left(u\right) \mathrm{du}$

$= - \cos \left(u\right) + c$

$= - \cos \left(\pi x\right) + c$