$ 0 0 Hallo, y=(x^2-4x)^(1/2) y'= 1/2 *(x^2-4x)^(-1/2) *( 2x-4) y'=1/2 *(x^2-4x)^(-1/2) *2 *(x-2) y'= (x-2) *(x^2-4x)^(-1/2)