Algebra

Fundamental algebraic concepts including equations, inequalities, and functions.

Advanced Topics

Quadratic Equations

What is a Quadratic Equation?

A quadratic equation has the form \( ax^2 + bx + c = 0 \), where \( a eq 0 \). The highest power of \( x \) is 2.

How to Solve Quadratics

  • Factoring: Find two numbers that multiply to \( c \) and add to \( b \).
  • Quadratic Formula: \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)
  • Completing the Square: Rearrange the equation to create a perfect square.

Graphs of Quadratics

The graph is a parabola, which looks like a "U" shape. The vertex is the highest or lowest point.

Real-World Quadratics

Quadratic equations are used in physics, engineering, and predicting how objects move, like a basketball shot or a rocket's path.

Key Formula

\[x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\]

Examples

  • Solve \( x^2 - 4 = 0 \): \( x^2 = 4 \), so \( x = 2 \) or \( x = -2 \).

  • The graph of \( y = x^2 - 2x + 1 \) is a parabola opening upward.

In a Nutshell

Quadratic equations involve \( x^2 \) and their graphs are parabolas.