5.5 The Substitution Rule/15

${\begin{aligned}\ \int sin(\pi t)dt\end{aligned}}$

${\begin{aligned}let\;u&=\pi t\\[2ex]du&=\pi dx\\[2ex]{\frac {1}{\pi }}du&=dx\end{aligned}}$

\int - \frac{1}{\pi} cos (\pi t) + c \end{align} </math>