2: If you changed the integral and used the trig integral approach, you should
get
![](gif3/eed3ab3.gif)
You could get directly to this stage using the substitution
y = tan(x) in the original integral. In any case, now you have an
integral for which there is a
standard procedure.
First you get rid of the nine either by factoring out or by the substitution
y = 3z, both lead to an elementary integral. Then comes the back
substitution and determining the domain of the integral.
Answer