Area Accumulation Function

$F(x)={\int }_a^{x}f(t)dt$ is the area accumulation function that gets the area from $[a,x]$ of the integrand $f(x)$.

It adds area as x moves along.

• Note that the function $f(t)$ is integrated with respect to $t$
• Thus, this will track $x$ as it moves along

Often used in FToC Part 2