Consider a quadratic equation with integer coefficients.
Is every integer a possible discriminant?
Prove it.
For b^24ac to be an even integer, b^2 must be even. Thus b must be even. Therefore, b^24ac = (2k)^24ac = 4(k^2ac) for some integer k. Hence, any even integer not divisible by 4 cannot be a discriminant.

Posted by Bractals
on 20050525 05:24:26 