SAT Math

Master the essential math concepts and problem-solving skills needed to excel on the SAT.

Advanced Topics

Quadratic Equations and Parabolas

Exploring Quadratics

Quadratic equations look like \( ax^2 + bx + c = 0 \). Their graphs are U-shaped curves called parabolas.

Solving Quadratics

  • Factoring: Split into two binomials.
  • Quadratic Formula: \( x = \frac{-b \pm \sqrt{b^2-4ac}}{2a} \)
  • Completing the Square
  • Graphing: Identify the vertex and direction (upward or downward).

Vertex and Axis of Symmetry

The vertex is the highest or lowest point: \( x = -\frac{b}{2a} \).

Why Quadratics Matter

  • Model projectile motion (throwing a ball)
  • Describe profit and revenue in business

Tips

  • Always check if the quadratic can be factored first.
  • Watch for negative signs and square roots!

Key Formula

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

Examples

  • Solving \( x^2 - 5x + 6 = 0 \) gives \( x = 2 \) and \( x = 3 \).

  • A ball thrown upward follows a parabolic path.

In a Nutshell

Quadratics model curves and help predict maximum or minimum values.

Key Terms

Parabola
The U-shaped curve of a quadratic function.
Vertex
The highest or lowest point on a parabola.