If you would like to know the discriminant of the quadratic equation 0 = -x^2 + 4x - 2, you can do this using the following steps:
0 = -x^2 + 4x - 2
0 = ax^2 + bx + c
a = -1, b = 4, c = -2
D =
b^2 - 4 a c = 4^2 - 4 (-1) (-2) = 16 - 4 * 2 = 16 - 8 = 8
The correct result would be b. 8.
