Math Problem Statement

f(x) = x+4/x^2-4

Solution

Let's analyze the function given:

f(x)=x+4x24f(x) = \frac{x + 4}{x^2 - 4}

Step 1: Identify Domain Restrictions

To find the domain of f(x)f(x), we need to determine where the function is undefined. The denominator cannot be zero:

x24=0x^2 - 4 = 0

Solve for xx:

x2=4    x=2orx=2x^2 = 4 \implies x = 2 \quad \text{or} \quad x = -2

Thus, the function is undefined at x=2x = 2 and x=2x = -2. The domain of f(x)f(x) is:

xR{2,2}x \in \mathbb{R} \setminus \{-2, 2\}

Step 2: Simplify the Function if Possible

Let's see if the function can be simplified. Notice that the denominator can be factored:

f(x)=x+4(x2)(x+2)f(x) = \frac{x + 4}{(x - 2)(x + 2)}

Since there are no common factors between the numerator and the denominator, this is already in its simplest form.

Step 3: Analyze Asymptotes

  • Vertical Asymptotes: These occur where the denominator is zero (and the numerator is not zero):

x=2andx=2x = 2 \quad \text{and} \quad x = -2

So, there are vertical asymptotes at x=2x = 2 and x=2x = -2.

  • Horizontal Asymptote: To find the horizontal asymptote, consider the degrees of the numerator and the denominator:
    • The numerator has degree 1.
    • The denominator has degree 2.

Since the degree of the denominator is greater than the degree of the numerator, the horizontal asymptote is:

y=0y = 0

Step 4: Identify Intercepts

  • x-intercept: Set f(x)=0f(x) = 0:

x+4x24=0    x+4=0    x=4\frac{x + 4}{x^2 - 4} = 0 \implies x + 4 = 0 \implies x = -4

So, there is an x-intercept at (4,0)(-4, 0).

  • y-intercept: Set x=0x = 0:

f(0)=0+4024=44=1f(0) = \frac{0 + 4}{0^2 - 4} = \frac{4}{-4} = -1

So, there is a y-intercept at (0,1)(0, -1).

Step 5: Summarize the Key Characteristics

  • Domain: xR{2,2}x \in \mathbb{R} \setminus \{-2, 2\}
  • Vertical Asymptotes: x=2,x=2x = 2, x = -2
  • Horizontal Asymptote: y=0y = 0
  • x-intercept: (4,0)(-4, 0)
  • y-intercept: (0,1)(0, -1)

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


Here are 5 related questions for further exploration:

  1. How do you find slant asymptotes for rational functions?
  2. What is the behavior of the function f(x)f(x) as xx \to \infty and xx \to -\infty?
  3. How would the graph of f(x)=x+4x24f(x) = \frac{x + 4}{x^2 - 4} look, including the intercepts and asymptotes?
  4. How do you determine whether a function is even, odd, or neither?
  5. How do you find the limit of a rational function at a vertical asymptote?

Tip: When dealing with rational functions, always check for both vertical and horizontal asymptotes to understand the behavior of the function better!

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Math Problem Analysis

Mathematical Concepts

Rational functions
Domain and range
Asymptotes
Intercepts

Formulas

None

Theorems

Vertical asymptotes
Horizontal asymptotes

Suitable Grade Level

Grades 10-12