Find the Discriminant f(x)=-7x^2+8x+2

$f (x) = - 7 x^{2} + 8 x + 2$

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 $c$ .

$8^{2} - 4 (- 7 \cdot 2)$

Step 3

Evaluate the result to find the discriminant.

Simplify each term.

Raise $8$ to the power of $2$ .

$64 - 4 (- 7 \cdot 2)$

Multiply $- 4 (- 7 \cdot 2)$ .

Multiply $- 7$ by $2$ .

$64 - 4 \cdot - 14$

Multiply $- 4$ by $- 14$ .

$64 + 56$

Add $64$ and $56$ .

$120$