Questions: Identify the domain of the following rational expression: (x+4)/(x^2+x-12)
Transcript text: Identify the domain of the following rational expression: $\frac{x+4}{x^{2}+x-12}$
Solution
Solution Steps
Step 1: Identify the Denominator
The given rational expression is
\[
\frac{x+4}{x^{2}+x-12}
\]
The domain of a rational expression is all real numbers except those that make the denominator zero. Therefore, we need to find the values of \(x\) that make the denominator zero.
Step 2: Solve for the Denominator
Set the denominator equal to zero and solve for \(x\):
\[
x^2 + x - 12 = 0
\]
Step 3: Factor the Quadratic
Factor the quadratic equation:
\[
x^2 + x - 12 = (x - 3)(x + 4) = 0
\]
Step 4: Find the Values that Make the Denominator Zero
Set each factor equal to zero:
\(x - 3 = 0 \Rightarrow x = 3\)
\(x + 4 = 0 \Rightarrow x = -4\)
These are the values that make the denominator zero.
Final Answer
The domain of the rational expression is all real numbers except \(x = 3\) and \(x = -4\). Therefore, the correct choice is:
\[
\boxed{\text{All real numbers except -4 and 3.}}
\]