The Quadratic Formula
Overview
Goal. Use the quadratic formula to solve any quadratic equation, and use the discriminant to predict whether it has two real solutions, one, or none.
Discriminant (definition). The value b² − 4ac inside the square root of the quadratic formula. Positive: two real solutions. Zero: one real solution. Negative: no real solutions.
Lesson Notes
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Lesson Video
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Interactive Activity
Goal. Solve quadratic equations with the quadratic formula — naming a, b, c with their signs — and read the discriminant to predict the number of real solutions.
Discriminant (definition). The value b² − 4ac inside the square root of the quadratic formula. Positive: two real solutions. Zero: one real solution. Negative: no real solutions.