Math Is Fun Forum
Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2014-11-07 23:29:55
- thedarktiger
- Member
- Registered: 2014-01-10
- Posts: 91
Algebraic problemo
Let a,b be real numbers such that 0<b <= a.
Prove that the equation x^2+ax-b=0 cannot have two integer roots.
Good. You can read.
Offline
#2 2014-11-08 00:37:02
- Olinguito
- Member
- Registered: 2014-08-12
- Posts: 649
Re: Algebraic problemo
Suppose both roots are integers. Then a and b must both be integers and the discriminant is a perfect square. We have
[list=*]
[*]
[/list]Thus, if we want to be a perfect square, we must have
[list=*]
[*]
[/list]
Last edited by Olinguito (2014-11-08 01:18:13)
Bassaricyon neblina
Offline
Pages: 1