Advanced Topics
In a nutshell: Quadratics pop up whenever something curves—like paths of thrown balls or profit calculations.
## Parabolas and More
Quadratic equations have the form \( ax^2 + bx + c = 0 \). Their graphs are U-shaped curves called parabolas.
### Solving Quadratics
- Factoring: Break into two binomials.
- Quadratic Formula: \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \)
- Completing the Square: Rearranging into a perfect square.
### Polynomials
- An expression with several terms, like \( 3x^3 + 2x^2 - x + 5 \).
### Real-World Application
Quadratics are used in physics (projectile motion), engineering, and finance (calculating profit).
### ACT Focus
Recognize graphs, solve for roots, and interpret word problems involving quadratics.
x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
Examples
- Solving \( x^2 - 5x + 6 = 0 \) by factoring: \( (x-2)(x-3) = 0 \), so \( x = 2 \) or \( x = 3 \)
- Using the quadratic formula on \( x^2 + 2x - 8 = 0 \) gives \( x = 2 \) or \( x = -4 \)