(3) I = ∫<0,1>dx∫<-x, x>√(x^2-y^2)dy= ∫<0,1>dx[(y/2)√(x^2-y^2)+(x^2/2)arcsin(y/x)]<-x, x>= ∫<0,1>(π/2)x^2dx = (π/6)[x^2]<0,1> = π/6
