1. The problem statement, all variables and given/known data Using Cauchy-Riemann equations show that f(z)=Re(z)Im(z)+i Im(z) is differentiable at only one point in C and find this point 2. Relevant equations 3. The attempt at a solution no idea about this question , can i set Re(z)=u Im(z)=v then U=uv V=v and the point is o ???