Math Problem Statement

$$$$ f\left(x\right) $$$$ \frac{x^2-4}{x^2-9}^{}rational functions (x-intercept)

Solution

You are asking about finding the xx-intercepts of a rational function. Let's work through the general steps for finding the xx-intercepts of a rational function using your specific function as an example.

Function Given:

f(x)=x24x29f(x) = \frac{x^2 - 4}{x^2 - 9}

Finding the xx-Intercept(s):

The xx-intercepts of a function occur where the function's value is zero. For a rational function f(x)=N(x)D(x)f(x) = \frac{N(x)}{D(x)}, the xx-intercepts occur where the numerator N(x)N(x) is zero, provided that the denominator D(x)D(x) is not zero at that point.

So, we solve: N(x)=0whereN(x)=x24N(x) = 0 \quad \text{where} \quad N(x) = x^2 - 4

Step 1: Set the Numerator Equal to Zero

x24=0x^2 - 4 = 0

This is a difference of squares, so we can factor it: (x2)(x+2)=0(x - 2)(x + 2) = 0

Thus, the solutions are: x=2andx=2x = 2 \quad \text{and} \quad x = -2

These are the potential xx-intercepts.

Step 2: Check the Denominator to Ensure These Points Are in the Domain

The function is undefined where the denominator is zero. So, we solve: D(x)=x29=0D(x) = x^2 - 9 = 0

Again, this is a difference of squares, so we can factor it: (x3)(x+3)=0(x - 3)(x + 3) = 0

Thus, the function is undefined at: x=3andx=3x = 3 \quad \text{and} \quad x = -3

Final Answer:

  • The function has xx-intercepts at x=2x = 2 and x=2x = -2.
  • However, the function is undefined at x=3x = 3 and x=3x = -3.

Would you like more details on this process, or do you have any specific questions?

Here are 5 related questions to deepen your understanding:

  1. How do you find the vertical asymptotes of a rational function?
  2. What happens to the graph of the function at points where it is undefined?
  3. How do horizontal asymptotes affect the long-term behavior of a rational function?
  4. What is the difference between a removable discontinuity and a vertical asymptote?
  5. How can you graph a rational function by identifying intercepts, asymptotes, and discontinuities?

Tip: When finding xx-intercepts for rational functions, always remember to check if the intercept lies within the domain by ensuring the denominator does not become zero at that point.

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Math Problem Analysis

Mathematical Concepts

Rational functions
Quadratic equations
Domain and range

Formulas

Difference of squares

Theorems

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Suitable Grade Level

Grades 11-12