Dividing Functions

Algebra-1

1. Fundamental Concepts

  • Definition: Dividing functions involves dividing one function by another, resulting in a new function.
  • Domain Consideration: The domain of the quotient function is all real numbers except where the denominator is zero.
  • Algebraic Division: When dividing polynomials, use long division or synthetic division methods.

2. Key Concepts

Basic Rule: $$(f \cdot g)(x) = \frac{f(x)}{g(x)}, \text{where } g(x) \neq 0$$
Degree Preservation: The degree of the numerator and denominator affects the form of the quotient function.
Application: Used to model rates of change and solve complex equations in physics and engineering.

3. Examples

Example 1 (Basic)

Problem: Simplify \(\frac{6x^2 + 9x}{3x}\)

Step-by-Step Solution:

  1. Factor out common terms: \(\frac{3x(2x + 3)}{3x}\)
  2. Simplify by canceling out common factors: \(2x + 3\)
Validation: Substitute \(x=1\) → Original: \(\frac{6+9}{3} = 5\); Simplified: \(2(1) + 3 = 5\) ✓

Example 2 (Intermediate)

Problem: \(\frac{x^2 - 4}{x - 2}\)

Step-by-Step Solution:

  1. Factor the numerator: \(\frac{(x + 2)(x - 2)}{x - 2}\)
  2. Simplify by canceling out common factors: \(x + 2\)
Validation: Substitute \(x=3\) → Original: \(\frac{9-4}{3-2} = 5\); Simplified: \(3 + 2 = 5\) ✓

4. Problem-Solving Techniques

  • Visual Strategy: Use graphs to visualize the behavior of the functions before and after division.
  • Error-Proofing: Always check for undefined points where the denominator equals zero.
  • Concept Reinforcement: Practice with a variety of functions including polynomials, rational functions, and trigonometric functions.