Moderate# Antidifferentiation: Finding $f(\theta )$

APCALC-7MZSNB

If $f^{ \prime \prime }\left( \theta \right) =\sin { \theta } $, $f^{ \prime }\left( \cfrac { \pi }{ 2 } \right) =0$, and $f\left( \cfrac { \pi }{ 2 } \right) =1$, what is $f(\theta )$ ?