A quadratic equation has a variable raised to the second power as its highest term, and its graph is a parabola. It can have two real solutions, one, or none, and the discriminant tells you which before you solve.
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.