1. Fundamental Concepts
- Definition: A transformed cubic function is a polynomial of degree three that has been modified through operations such as shifting, stretching, or reflecting.
- Zeros: The zeros of a function are the values of \(x\) for which the function equals zero.
- Transformations: Transformations can affect the location and number of zeros of a cubic function.
2. Key Concepts
Basic Rule: $$f(x) = a(x - h)^3 + k$$
Degree Preservation: The highest degree in the result matches input
Application: Used to model real-world phenomena such as motion and engineering problems
3. Examples
Example 1 (Basic)
Problem: Find the zeros of the function \(f(x) = (x - 2)^3\).
Step-by-Step Solution:
- Set the function equal to zero: \((x - 2)^3 = 0\)
- Solve for \(x\): \(x - 2 = 0 \Rightarrow x = 2\)
Validation: Substitute \(x = 2\) → Original: \((2 - 2)^3 = 0\); Simplified: \(0 = 0\) ✓
Example 2 (Intermediate)
Problem: Find the zeros of the function \(g(x) = 2(x + 1)^3 - 8\).
Step-by-Step Solution:
- Set the function equal to zero: \(2(x + 1)^3 - 8 = 0\)
- Solve for \(x\): \(2(x + 1)^3 = 8 \Rightarrow (x + 1)^3 = 4 \Rightarrow x + 1 = \sqrt[3]{4} \Rightarrow x = \sqrt[3]{4} - 1\)
Validation: Substitute \(x = \sqrt[3]{4} - 1\) → Original: \(2(\sqrt[3]{4})^3 - 8 = 2 \cdot 4 - 8 = 8 - 8 = 0\); Simplified: \(0 = 0\) ✓
4. Problem-Solving Techniques
- Visual Strategy: Graph the function to visualize the transformations and their effects on the zeros.
- Error-Proofing: Double-check each step of the solution process, especially when dealing with cube roots and other complex expressions.
- Concept Reinforcement: Practice with various types of transformations to understand how they affect the zeros of a cubic function.