SOLUTION: Find k such that the equation x^2 - kx + 4 = 0 has a repeated real solution.
Let me see.
I think the discriminant applies here.
b^2 - 4ac = 0
k^2 - 4(1)(4) =
(A) It is correct.
(B) Both k= -4 and k= 4 give repeated root.
In case k= -4, the polynomial is
x^2 + 4x + 4 = with repeated real root x= -2.
In case k= 4, the polynomial is
x^2 - 4x + 4 = with repeated real root x= 2.