Questions: Find the domain of the function.
f(x) = sqrt(x-3) / (x+10)(x-11)
[3, infinity)
(-10,11) union (11, infinity)
(11, infinity)
(-10,3] union [3, infinity)
[3,11) union (11, infinity)
Transcript text: Find the domain of the function.
\[
f(x)=\frac{\sqrt{x-3}}{(x+10)(x-11)}
\]
$[3, \infty)$
$(-10,11) \cup(11, \infty)$
$(11, \infty)$
$(-10,3] \cup[3, \infty)$
$[3,11) \cup(11, \infty)$
Solution
Solution Steps
To find the domain of the function \( f(x) = \frac{\sqrt{x-3}}{(x+10)(x-11)} \), we need to consider the constraints imposed by the square root and the denominator. The expression under the square root, \( x-3 \), must be non-negative, so \( x \geq 3 \). Additionally, the denominator cannot be zero, so \( x \neq -10 \) and \( x \neq 11 \). Combining these conditions, the domain is \( [3, 11) \cup (11, \infty) \).
Step 1: Determine the Domain of the Numerator
The numerator of the function is \(\sqrt{x-3}\). The expression under the square root, \(x-3\), must be non-negative for the square root to be defined. Therefore, we have:
\[
x - 3 \geq 0
\]
Solving this inequality gives:
\[
x \geq 3
\]
Thus, the domain of the numerator is \([3, \infty)\).
Step 2: Determine the Domain of the Denominator
The denominator of the function is \((x+10)(x-11)\). This expression is undefined when either factor is zero. Therefore, we need to find the values of \(x\) that make the denominator zero:
\(x + 10 = 0 \Rightarrow x = -10\)
\(x - 11 = 0 \Rightarrow x = 11\)
Thus, the denominator is undefined at \(x = -10\) and \(x = 11\).
Step 3: Combine the Conditions
The function \(f(x)\) is defined where both the numerator is defined and the denominator is non-zero. Therefore, we combine the conditions:
\(x \geq 3\) (from the numerator)
\(x \neq -10\) and \(x \neq 11\) (from the denominator)
The domain of the function is the intersection of these conditions:
From \(x \geq 3\), we have \([3, \infty)\).
Excluding \(x = 11\) from \([3, \infty)\), we get \([3, 11) \cup (11, \infty)\).