Chapter 5.6, Problem 68ES

(a) Over what open interval does the formula

$F\left(x\right)={\displaystyle {\int }_1^x\frac{1}{t^2-9}dt}$

represent an antiderivative of

$f\left(x\right)=\frac{1}{x^2-9}$ ?

(b) Find a point where the graph of $F$ crosses the $x\text{-axis}$ .