# Math Help - Real Roots

1. ## Real Roots

Hi! I've tried to solve this question, but I came to the conclusion that I couldn't so I gave up! I hope you can help me with this one

The equation x^2 - 2kx + 1 = 0 has two distinct real roots. Find the set of all possible values of k.

Thanks,
Amine.

2. Hi

The discriminant is $\Delta = (-2k)^2-4 = 4(k^2-1)$

The equation $x^2 - 2kx + 1 = 0$ has two distinct real roots if $\Delta > 0$

Can you go on ?

3. Does the final answer give 1/2(x + 1/x)?