Math Problem Statement

Find the domain of the following rational function. Upper F left parenthesis x right parenthesis equals StartFraction 4 x left parenthesis x minus 6 right parenthesis Over 3 x squared minus 11 x minus 4 EndFraction

Solution

To find the domain of the rational function F(x)=4x(x6)3x211x4,F(x) = \frac{4x(x - 6)}{3x^2 - 11x - 4}, we need to identify values of xx that make the denominator equal to zero, since division by zero is undefined.

Step 1: Set the denominator equal to zero

The denominator is: 3x211x4=03x^2 - 11x - 4 = 0 To solve this quadratic equation, we'll use the quadratic formula: x=b±b24ac2a,x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}, where a=3a = 3, b=11b = -11, and c=4c = -4.

Step 2: Calculate the discriminant

b24ac=(11)24(3)(4)=121+48=169.b^2 - 4ac = (-11)^2 - 4(3)(-4) = 121 + 48 = 169.

Step 3: Find the roots using the quadratic formula

x=(11)±1692(3),x = \frac{-(-11) \pm \sqrt{169}}{2(3)}, x=11±136.x = \frac{11 \pm 13}{6}. This gives us: x=246=4andx=26=13.x = \frac{24}{6} = 4 \quad \text{and} \quad x = \frac{-2}{6} = -\frac{1}{3}.

Step 4: Determine the domain

The values x=4x = 4 and x=13x = -\frac{1}{3} make the denominator zero, so they must be excluded from the domain.

Therefore, the domain of F(x)F(x) is all real numbers except x=4x = 4 and x=13x = -\frac{1}{3}.

Final Answer

The domain of F(x)F(x) is: {xR:x4 and x13}.\{ x \in \mathbb{R} : x \neq 4 \text{ and } x \neq -\frac{1}{3} \}.

Would you like more details or have any questions?

5 Related Questions

  1. How do you find the domain of a rational function in general?
  2. What happens to the function's behavior as xx approaches 4 or 13-\frac{1}{3}?
  3. How can we factor a quadratic expression like 3x211x43x^2 - 11x - 4 without using the quadratic formula?
  4. How does the numerator affect the domain of a rational function?
  5. How do you determine the vertical asymptotes of a rational function?

Tip

When finding the domain of a rational function, always start by identifying values that make the denominator zero, as these values are excluded from the domain.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Rational Functions
Quadratic Equations
Domain of a Function

Formulas

Quadratic Formula: x = (-b ± √(b^2 - 4ac)) / 2a

Theorems

Quadratic Formula
Domain of Rational Functions

Suitable Grade Level

Grades 9-11