College Algebra

College Algebra covers fundamental algebraic concepts, including functions, equations, and inequalities, essential for higher-level mathematics.

Advanced Topics

Quadratic Equations and Applications

Exploring Quadratic Equations

Quadratic equations have the form \(ax^2 + bx + c = 0\). They appear everywhere—from physics to finance.

Solving Methods

  • Factoring: Find two numbers that multiply to \(ac\) and add to \(b\).
  • Quadratic Formula: \[x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\]
  • Completing the Square: Rearrange and solve by taking square roots.

Real-World Applications

  • Projectile motion (sports, physics)
  • Optimizing area or profit

Visualizing Quadratics

The graph is a parabola—its vertex shows the maximum or minimum value.

Key Formula

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

Examples

  • Solve \(x^2 - 5x + 6 = 0\) by factoring: \((x-2)(x-3) = 0\), so \(x=2\) or \(x=3\).

  • A ball thrown upward follows \(h(t) = -16t^2 + 32t + 5\); its height at any time \(t\) is found by solving this quadratic.

In a Nutshell

Quadratic equations solve problems with squared variables and appear in many real-life contexts.

Key Terms

Discriminant
The value \(b^2 - 4ac\) in the quadratic formula, which determines the number and type of solutions.
Vertex
The highest or lowest point of a parabola.