Question #N188
The equation $x^2+4x-9=0$ can be solved by using the quadratic formula. What is the value of the discriminant of this equation?
A. -40
B. 16
C. 40
D. 64
Correct Answer is: C
The quadratic formula states that for the equation $ax^2 + bx + c = 0$, the discriminant is $b^2 - 4ac$. In this case, $a = 1$, $b = 4$, and $c = -9$. Therefore, the discriminant is $4^2 - 4(1)(-9) = 16 + 36 = 52$.