Find the Discriminant -4x^2-12x-9=0

$- 4 x^{2} - 12 x - 9 = 0$

Step 1

The discriminant of a quadratic is the expression inside the radical of the quadratic formula.

$b^{2} - 4 (a c)$

Step 2

Substitute in the values of $a$ , $b$ , and $c$ .

${(- 12)}^{2} - 4 (- 4 \cdot - 9)$

Step 3

Evaluate the result to find the discriminant.

Simplify each term.

Raise $- 12$ to the power of $2$ .

$144 - 4 (- 4 \cdot - 9)$

Multiply $- 4 (- 4 \cdot - 9)$ .

Multiply $- 4$ by $- 9$ .

$144 - 4 \cdot 36$

Multiply $- 4$ by $36$ .

$144 - 144$

Subtract $144$ from $144$ .

$0$