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Hello what is the answer to this and the domain

Hello what is the answer to this and the domain-example-1
User Kalugny
by
3.3k points

1 Answer

15 votes
15 votes

We are given the following functions:


\begin{gathered} f(x)=7\sqrt[]{x}+6 \\ g(x)=x+6 \end{gathered}

We are asked to determine the composite function:


(f\circ g)(x)

The composition of functions is equivalent to:


(f\circ g)(x)=f(g(x))

Therefore, we replace the value of "x" in function "f" for the function "g", therefore, we get:


(f\circ g)(x)=f(g(x))=7\sqrt[]{x+6}+6

Since we can't simplify any further this is the composition.

Now we are asked to determine the domain of this function. Since we have a square root, the domain must be the values of "x" where the term inside the radical is greater or equal to zero, therefore, we have:


x+6\ge0

Now we solve for "x" by subtracting 6 from both sides:


x\ge-6

Therefore, the domain is:


\lbrack-6,\infty)

User Kragan
by
2.3k points
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