f(x)= 1/(1+x)f'(x) = -1/(1+x)^2f''(x) =2/(1+x)^3f'''(x) =-6/(1+x)^4......f^(n)(x) = (-1)^n . n!/ (1+x)^(n+1)g(x) = 1/(1-x)g^(n)(x) = n!/ (1-x)^(n+1)
