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Overview
Mathematics II
11. CC.HSA.REI.B.4
11.3 Using quadratic formula to solve quadratic equations
The Quadratic Formula
The quadratic formula solves any equation of the form a x squared plus b x plus c equals zero.
What You'll Learn
The quadratic formula solves any equation written as a x squared plus b x plus c equals 0.
It gives both solutions directly from the coefficients a, b, and c.
The discriminant, b squared minus 4 a c, tells you how many real solutions there are.
A positive discriminant gives two solutions, zero gives one, and a negative gives none that are real.
It works even when the equation does not factor neatly.
What You'll Practice
1
Plugging a, b, and c values into the quadratic formula
2
Solving equations with positive and negative coefficients
3
Simplifying square roots and reducing fractions in answers
4
Working with equations that yield imaginary number solutions
Why This Matters
The quadratic formula is your universal tool for solving any quadratic equation, whether it factors neatly or not. Mastering this formula prepares you for advanced algebra, calculus, physics, and engineering courses where quadratic relationships appear constantly.
Before You Start — Make Sure You Can:
This Unit Includes
4 Video lessons
Practice exercises
Learning resources
Skills
Quadratic Formula
Quadratic Equations
Standard Form
Radicals
Simplification
Imaginary Numbers
Algebraic Manipulation
SD Curriculum Aligned