integrals.wolfram.com   Use one of Mathematica's 2500+ functions FREE online

Integrate[x/(a*Sqrt[c^2 - d^2*x^2]), x] ==
-(Sqrt[(c - d*x)*(c + d*x)]/(a*d^2))

                  x
Integrate[------------------, x] == 
                  2    2  2
          a Sqrt[c  - d  x ]

  Sqrt[(c - d x) (c + d x)]
-(-------------------------)
               2
            a d