Questions: Find the domain of the function.
g(x) = 2x / (x^2 - 9)
Transcript text: Find the domain of the function.
\[
g(x)=\frac{2 x}{x^{2}-9}
\]
Solution
Solution Steps
To find the domain of the function \( g(x) = \frac{2x}{x^2 - 9} \), we need to determine the values of \( x \) for which the function is defined. The function is undefined when the denominator is zero. Therefore, we need to find the values of \( x \) that make \( x^2 - 9 = 0 \) and exclude them from the domain.
Step 1: Identify the Function
We are given the function \( g(x) = \frac{2x}{x^2 - 9} \). To find the domain, we need to determine where this function is defined.
Step 2: Find the Denominator
The function is undefined when the denominator is equal to zero. Thus, we set the denominator equal to zero:
\[
x^2 - 9 = 0
\]
Step 3: Solve for Critical Points
Solving the equation \( x^2 - 9 = 0 \) gives us:
\[
x^2 = 9 \implies x = \pm 3
\]
This means the function is undefined at \( x = -3 \) and \( x = 3 \).
Step 4: Determine the Domain
The domain of \( g(x) \) excludes the points where the function is undefined. Therefore, the domain can be expressed in interval notation as:
\[
(-\infty, -3) \cup (-3, 3) \cup (3, \infty)
\]
Final Answer
The domain of the function \( g(x) \) is
\[
\boxed{(-\infty, -3) \cup (-3, 3) \cup (3, \infty)}
\]