Which graph shows a quadratic function with a discriminant value of 0?

Aquadratic function that has a discriminant equal to zero is, for example,  f (x) = x ^ 2.  because the discriminant is given by  b ^ 2 - 4 * a * c  for this case,  b = 0  a = 1  c = 0  substituting  b ^ 2 - 4 * a * c = (0) ^ 2 - 4 * (1) * (0) = 0  the graph for this function is attached to the solution.