What is the differentiability of f(z) using Cauchy-Riemann equations?

[ak123456]

Homework Statement

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

Homework Equations

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 ?

 

[dx]

If z = x + iy, then Re(z) = x and Im(z) = y.