Question

Prove the following: a) (∀ z1, z2 ∈ ℂ) z1 + z2 = z1 + z2. (Use cartesian form). b) (∀ z1, z2 ∈ ℂ) z1z2 = z1 z2. (Use polar form) Ps - the 1's and 2's beside the z's are small and lower numbers next to the z's - I hope you get what I mean.