# What is the discriminant of x^2 = 4?

Sep 11, 2014

First this quadratic equation must be put in standard form.

$a {x}^{2} + b x + c = 0$

To accomplish this you have to subtract 4 from both sides of the equation to end up with ...

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

We now see that $a = 1 , b = 0 , c = - 4$

Now substitute in the values for a, b, and c in the discriminant

Discriminant: ${b}^{2} - 4 a c = {\left(0\right)}^{2} - 4 \left(1\right) \left(- 4\right) = 0 + 16 = 16$

Please see the following link for another example usage of the discriminant.