Originally Posted by

**Arka** Hey guys,

I'm stuck on this tough question ......

Find the values of a which make x^2 - ax + 1 - 2(a^2) always positive for all real x.

I made the expression equal to 0 ..and then since x is real, the discriminant should be greater than or equal to 0 . I manipulated this inequality to get that x lies between -(2/3) and +(2/3), which is actually the answer given , but I am not satisfied since they said that the the expression should be greater than 0 but I set it equal to 0 .