Consider the complex plane \(\mathbb {C}\) with the Euclidean metric. Let \(f:\mathbb {C}\to \mathbb {C}\) be a complex-analytic mapping and \(z\in \mathbb {C}\) be a point such that \(f'(z)\ne 0\). Show that the derivative \(Df_z:T_z\mathbb {C}\to T_{f(z)}\mathbb {C}\) preserves angles.
Question
Math 6510 • Differentiable Manifolds
Fall 1996 • Question 5