Questions: Consider the following functions.
f(x) = sqrt(x-4) and g(x) = sqrt[3]x
Find the formula for (f+g)(x) and simplify your answer. Then find the domain for (f+g)(x). Round your answer to two decimal places, if necessary.
Transcript text: Consider the following functions.
\[
f(x)=\sqrt{x-4} \text { and } g(x)=\sqrt[3]{x}
\]
Find the formula for $(f+g)(x)$ and simplify your answer. Then find the domain for $(f+g)(x)$. Round your answer to two decimal places, if necessary.
Solution
Solution Steps
To find the formula for \((f+g)(x)\), we need to add the two given functions: \(f(x) = \sqrt{x-4}\) and \(g(x) = \sqrt[3]{x}\). The domain of \((f+g)(x)\) is determined by the intersection of the domains of \(f(x)\) and \(g(x)\). For \(f(x)\), \(x\) must be greater than or equal to 4, and for \(g(x)\), \(x\) can be any real number. Therefore, the domain of \((f+g)(x)\) is \(x \geq 4\).
Step 1: Find the Formula for \((f+g)(x)\)
We have the functions defined as follows:
\[
f(x) = \sqrt{x - 4}
\]
\[
g(x) = \sqrt[3]{x}
\]
To find \((f+g)(x)\), we add the two functions:
\[
(f+g)(x) = f(x) + g(x) = \sqrt{x - 4} + \sqrt[3]{x}
\]
Thus, the formula for \((f+g)(x)\) is:
\[
(f+g)(x) = \sqrt{x - 4} + x^{1/3}
\]
Step 2: Simplify the Expression
The expression \((f+g)(x)\) does not simplify further in a meaningful way, so we retain it as:
\[
(f+g)(x) = x^{1/3} + \sqrt{x - 4}
\]
Step 3: Determine the Domain of \((f+g)(x)\)
The domain of \(f(x)\) requires that:
\[
x - 4 \geq 0 \implies x \geq 4
\]
The function \(g(x)\) is defined for all real numbers. Therefore, the domain of \((f+g)(x)\) is determined by the more restrictive condition from \(f(x)\):
\[
\text{Domain of } (f+g)(x) = [4, \infty)
\]
Final Answer
The formula for \((f+g)(x)\) is:
\[
\boxed{(f+g)(x) = \sqrt{x - 4} + x^{1/3}}
\]
The domain of \((f+g)(x)\) is:
\[
\boxed{[4, \infty)}
\]