If x=6 is the only x intercept of the graph of a quadration equation which statement best describes the describes the discrimination of the equation

In a quadratic equation , we use the quadratic formula to find the solutions x = (-b ± √(b2 - 4ac)) / 2a  where a, b, and c are coefficients of the equation ax2 + bx + c = 0  Since x=6 is the only x-intercept, the equation would be (x - 6)(x - 6) = 0  Expanding this out, we get x2 - 12x + 36 = 0  In this equation, a = 1b = -12c = 36 Now the discriminant is the square-root part of the formula: b2 - 4ac  Now plug in the values of a,b, and c into the discriminant. (-12)2 - 4(1)(36) = 144 - 144 = 0 This number is under the square-root.  The square-root of 0 is 0.  Your answer is (A).
(I had the same question in math last week)