Math Dictionary / Quadratic Equation

Quadratic Equation

A quadratic equation is an equation that can be written in the form ax^2 + bx + c = 0, where a is not 0.

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What it means

Its graph is a parabola, and it may have zero, one, or two real solutions.

Also called: second-degree equation

Examples

x^2 – 5x + 6 = 0
2x^2 + 3x – 1 = 0
x^2 = 9 is quadratic

Common mistake

Make one side 0 before factoring or using the quadratic formula.

Try one

Question: What values solve x^2 – 9 = 0?

Show answer

x^2 = 9, so x = -3 or x = 3.

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