i cant seem to figure out what to sub in into the integral of x/(((x+2)^2)+9). PAny help greatly apprehiated asap.... Thanks!
$\displaystyle \int \frac{x}{\sqrt{(x+2)^2+9}} dx$
Let $\displaystyle t=x+2$ so,
$\displaystyle \int \frac{t-2}{\sqrt{t^2+9}} dt = \int \frac{t}{\sqrt{t^2+9}} dt - 2 \int \frac{1}{\sqrt{t^2+9}} dt$
The first integral use the substitution $\displaystyle \xi = t^2$ and the second is an inverse sine integral.