Find ( int frac{3dx}{9+x^2} ).

Discussion

Find ( int frac{dx}{x^2+4} ).
Find ( int frac{7dx}{x^2-9} ).
Find ( int frac{(x+3)}{2x^2+6x+7} dx ).
Find ( int frac{dx}{x^2-8x+20} ).
Integrate ( frac{dx}{ sqrt{x^2+36}} ).
Find ( int frac{dx}{ sqrt{5-x^2}} ).
Find ( int frac{10 ,dx}{ sqrt{x^2-25}} ).
Find ( int frac{3dx}{9+x^2} ).
Find ( int frac{8 dx}{x^2-16} ).
Find ( int frac{2 dx}{x^2-64} ).