Let \( f^{\prime \prime}(x)=-5 \cos (x) \).
(a) Find the most general formula for \( f^{\prime}(x) \). If an arbitrary constant must be used here, use an upper-case "C".
\[
f^{\prime}(x)=
\]
\( \square \)
(b) Based on your answer to (a), find the most general formula for \( f(x) \). If another new arbitrary constant must be used here, use an upper-case "D".
\[
f(x)=
\]
\( \square \)