What is the discriminant of $x^{2} = 4$ $x^2 = 4$ ?

Question

6618 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2014-09-11T05:34:33

First this quadratic equation must be put in standard form.

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

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

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

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

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

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

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

What is the discriminant of x2=4x^2 = 4?