For the quadratic equation 2x^2 - 4x + k = 0 to have real roots, what must be the condition on k?
Answer: C. k ? 8
The condition for real roots is that the discriminant must be non-negative. Here, the discriminant is (-4)^2 - 4(2)(k) = 16 - 8k. Setting this ? 0 gives k ? 2.