Primitive of Constant Multiple of Function/Proof 1

Proof
From Linear Combination of Integrals:
 * $\displaystyle \int \paren {\lambda \map f x + \mu \map g x} \rd x = \lambda \int \map f x \rd x + \mu \int \map g x \rd x$

The result follows by setting $\lambda = c$ and $\mu = 0$.