(a) Let u, v be two non-zero complex numbers. Prove that if |u| = |v|, then 2 arg(u + v) = argu + arg v (b) Find the moduli and arguments of the complex numbers 11 and 12 Hence evaluate arg(1+√2+i). 1-i 6. Let z₁,z₂ and 2, be non-zero complex numbers. If |z₁|=|z₂|=|z3|, show that