1. The problem statement, all variables and given/known data Prove that √ab = √a × √b is possible for all the value of a and b except when both are less than 0 at the same time . 2. Relevant equations √(-a)b =(√a)i × b = (√ab)i 3. The attempt at a solution I don't know how to start, to prove this type of question, but i think that there must be an answer for this.