Find all real values of k such that x^2 - 4kx + k = 0 has real roots.
discrimnant of the Quadratic Equation must be positive
\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)
b2-4ac is the discriminant (-4k)^2 - 4 (1)(k) >0
16 k^2 - 4k > 0
4k (4k-1) > 0
k = 0 or 1/4