Math Problem Statement

(x^3 + 27)/(x+3) find VA

Solution

To find the vertical asymptotes (VA) of the given rational function:

f(x)=x3+27x+3f(x) = \frac{x^3 + 27}{x + 3}

Steps:

  1. Factor the numerator if possible: The numerator x3+27x^3 + 27 is a sum of cubes. Using the formula: a3+b3=(a+b)(a2ab+b2)a^3 + b^3 = (a + b)(a^2 - ab + b^2) with a=xa = x and b=3b = 3, we factor x3+27x^3 + 27: x3+27=(x+3)(x23x+9)x^3 + 27 = (x + 3)(x^2 - 3x + 9)

  2. Simplify the rational function: Substituting the factorized form: f(x)=(x+3)(x23x+9)x+3f(x) = \frac{(x + 3)(x^2 - 3x + 9)}{x + 3} For x3x \neq -3, the (x+3)(x + 3) terms cancel, leaving: f(x)=x23x+9f(x) = x^2 - 3x + 9

  3. Identify vertical asymptotes: Vertical asymptotes occur when the denominator equals zero and the numerator does not simultaneously equal zero. Here: Denominator: x+3=0x=3\text{Denominator: } x + 3 = 0 \quad \Rightarrow \quad x = -3 However, since x+3x + 3 cancels with the numerator, x=3x = -3 is not a vertical asymptote. Instead, it is a hole in the graph.

Final Answer:

This function has no vertical asymptotes, only a hole at x=3x = -3.


Do you want me to clarify anything further or analyze other aspects of this function?


Related Questions:

  1. What are the horizontal asymptotes of this function?
  2. How do we find and represent the hole in the graph?
  3. What is the end behavior of the simplified function x23x+9x^2 - 3x + 9?
  4. Can this method be used for other cubic polynomials?
  5. What is the significance of removing common factors in rational functions?

Tip:

Always check if the numerator and denominator share common factors before concluding the presence of vertical asymptotes.

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Math Problem Analysis

Mathematical Concepts

Rational Functions
Vertical Asymptotes
Factorization
Sum of Cubes

Formulas

a^3 + b^3 = (a + b)(a^2 - ab + b^2)
x^3 + 27 = (x + 3)(x^2 - 3x + 9)

Theorems

Vertical Asymptote Theorem
Factorization of Sum of Cubes

Suitable Grade Level

Grades 10-12