Answer
Constant functions are antiderivatives of zero functions (functions of the form $f(x)=0$).
Work Step by Step
If $F(x)$ is an antiderivative of $f(x)$, that is $ F'(x)=f(x)$, then the indefinite integral of f is
$\displaystyle \int f(x)dx=F(x)+C.$
If $ F(x)=a,\quad$ (a constant function)
then$\quad F'(x)=0,\quad$ (a zero function).
So, constant functions are antiderivatives of zero functions (functions of the form $f(x)=0$).
