Answer
True
Work Step by Step
The function is an integration in the form
$$A(x)=\int_{a}^{x} f(t) d t$$
By taking the differentiation we get the same function:
$$A^{\prime}(x)=\frac{d}{d x} \int_{a}^{x} f(t) d t=f(x)$$
Hence, the answer is true.
