<h3>Answer: choice A</h3>
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Explanation:
The idea is to start with f(x), then replace every copy of x with g(x) so that you end up with the composition function as shown below.
The notation is the same as
I prefer as it is more descriptive.
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Now onto computing the domain. We want to avoid dividing by zero, and we want to avoid taking the square root of a negative number.
This means the expression x+3 must be larger than 0. That way will also be larger than 0.
If x+3 > 0, then x > -3 after subtracting 3 from both sides.
As long as x is larger than -3, then it is a valid input to the composite function