Advanced math vocabulary

Quadratic Equation

Pronunciation: kwah-DRAT-ik ee-KWAY-zhun

A quadratic equation is an equation that can be written ax² + bx + c = 0 with a not equal to zero.

Symbols and notationax² + bx + c = 0
Subject
Grade bands
Difficulty

Advanced

Profession trailEngineers & Architects

Plain language

What it means

A quadratic equation is an equation that can be written ax² + bx + c = 0 with a not equal to zero.

Formal meaning

Mathematical definition

A degree-two polynomial equation has solutions determined by factoring, completing the square, graphing, or the quadratic formula.

Where it fits

Its place in mathematics

Quadratics model area, projectile motion, optimization, parabolic shapes, and many nonlinear relationships.

Why it matters

The practical reason to learn it

They are a first major example of equations that may have two, one, or no real solutions.

A degree-two graphThe graph of a quadratic function is a parabola whose intercepts correspond to real solutions.

Worked example

Solve by factoring

Solve x² - 5x + 6 = 0.

  1. Find two numbers that multiply to 6 and add to -5.
  2. Factor as (x - 2)(x - 3) = 0.
  3. Set each factor equal to zero.
Answer

x = 2 or x = 3.

Real-life example

Where this appears

An engineer can use a quadratic model to estimate the path of an object under simplified conditions.

Common mistake

What to watch for

Forgetting that taking a square root can produce both a positive and a negative solution.

Memory tip

Keep this in mind

After solving, substitute each candidate into the original equation.

Little-known fact

Keep curiosity alive

The quadratic formula works for every quadratic equation, even when factoring is inconvenient.

A profession that uses this idea

Curved paths often use quadratics

Engineers use quadratic models for simplified trajectories, area constraints, and optimization problems.

Explore Engineers & Architects

Follow the learning trail

Prerequisites, related ideas and next concepts

People behind the ideas

Related Math Heroes

Brahmagupta

Brahmagupta was mathematician and astronomer. He gave systematic rules for arithmetic with zero and negative numbers and worked on quadratic equations and cyclic quadrilaterals.

Al-Khwarizmi

A scholar whose systematic writing on calculation and equation solving helped shape algebra and whose name became the root of the word algorithm.

Put the idea to work

Related practice