Solution
= Solution
The <fundamental theorem of calculus>, using continuity of $f$ near $x$, gives
$$
\boxed{\frac{dF}{dx}=f(x).}
$$
The lower endpoint $a$ is constant, so it contributes no additional term.
= Solution
The <fundamental theorem of calculus>, using continuity of $f$ near $x$, gives
$$
\boxed{\frac{dF}{dx}=f(x).}
$$
The lower endpoint $a$ is constant, so it contributes no additional term.