Use the limit definition of derivative to determine whether the function f(z)=(\operatorname{Re} z)^{2}f(z)=(Rez) 2 is complex-differentiable anywhere it the complex plane (consider the vertical and horizontal limits for \Delta f / \Delta z,Δf/Δz, as we did in class). Is it analytic anywhere? Check your answer using Cauchy-Riemann equations, u_{x}=v_{y}, u_{y}=-v_{x}u x =v y ,u y =−v x .