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

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Answer 1 · 2014-09-11T05:34:33

First this quadratic equation must be put in standard form.

$ax^2+bx+c=0$

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

$x^2-4=0$

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

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

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

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

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