Question

Using Vieta's formula, given
a+b+c =1
ab+bc+ac=-4
abc=-3

How do I find a+b, b+c and a+c?

Answer 1

you could start by noting that
(a+b+c)^2 = 1^2
a^2 + b^2 + c^2 + 2(ab+ac+bc) = 1
a^2 + b^2 + c^2 = 9

Whatever you do, it ain't gonna be pretty.