***The complete question is: Let f(x)= sqrt 6x and g(x)=x+3 smallest number that is in the domain of f(g(x))***
Answer: The smallest number that is in the domain is -3.
Step-by-step explanation:
Given functions:
![f(x) = √(6x)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/8a09kk4m0a8cof6ofwwkqhq2d3n8qcqmyy.png)
![g(x) = x + 3](https://img.qammunity.org/2019/formulas/mathematics/middle-school/eqgtoms00jpqdml9ay4kejxzeciriqzj8v.png)
To find f(g(x)), put g(x) in f(x) as follows:
![f(g(x)) = f(x+3) = √(6(x+3)) = √(6x + 18)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/dm7sp5ulx8v5257f06ytsx42lnpsxy78nd.png)
As (6x+18) is in square-root (and square-root of a negative number is an imaginary value), therefore, the domain should be the following:
![6x + 18 \geq 0\\6x \geq -18\\x \geq -3](https://img.qammunity.org/2019/formulas/mathematics/middle-school/ogy3m3vrwlfd5atqbbjcnsivuat0bk1i6a.png)
Therefore, the domain is [-3, +∞).
So the smallest number that is in the domain is -3.