Identify values: Identify the values of a, b, and c from the quadratic equation in the form ax2+bx+c=0. Comparing 7x2−4x−4=0 with ax2+bx+c=0, we find: a=7b=−4c=−4
Calculate discriminant: Calculate the discriminant using the formula D=b2−4ac.Substitute 7 for a, −4 for b, and −4 for c in the formula.D=(−4)2−4×7×(−4)
Simplify discriminant: Simplify the discriminant.D=16−(−112)D=16+112D=128