Find the Discriminant -9x^2-9x-6=0

$- 9 x^{2} - 9 x - 6 = 0$

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 $c$ .

${(- 9)}^{2} - 4 (- 9 \cdot - 6)$

Step 3

Evaluate the result to find the discriminant.

Simplify each term.

Raise $- 9$ to the power of $2$ .

$81 - 4 (- 9 \cdot - 6)$

Multiply $- 4 (- 9 \cdot - 6)$ .

Multiply $- 9$ by $- 6$ .

$81 - 4 \cdot 54$

Multiply $- 4$ by $54$ .

$81 - 216$

Subtract $216$ from $81$ .

$- 135$