Evaluate the indefinite integral ∫xx2+9dx\int \frac{x}{\sqrt{x^2+9}} dx∫x2+9xdx.
x2+9+C\sqrt{x^2+9} + Cx2+9+C
12x2+9+C\frac{1}{2}\sqrt{x^2+9} + C21x2+9+C
2x2+9+C2\sqrt{x^2+9} + C2x2+9+C
13x2+9+C\frac{1}{3}\sqrt{x^2+9} + C31x2+9+C