Answer: the fourth option; all the real values except x = 7 and the x for which f(x) = - 3
Explanation:
1) the composed function (g ° f) )x= is the application of the function g (x) to the function f(x), this is you first apply f(x) and then apply g(x): g [f(x) ]
2) So the domain is the set of values for which f(x) is defined and then those values of f(x) for which g(x) is defined.
3) The values of x for which f(x) is defined is all the real values except x = 7.
4) The values of f(x) for which g(x) is defined are all the values of f(x) except f(x) = - 3.
5) So, the domain of the composed function is all the real values except x = 7 and the x for which f(x) = - 3
6) Important remark: notice that there is an error in the statements listed, because saying that the domain is all the real values except x ≠ 7 and f(x) ≠ - 3 means that tha domain is only x = 7 and f(x) = - 3, when what they meant was that the composed function is not defined for x = 7 and f(x) = - 3 (this is a bad use of double negation which is a good expample of why double negation must be avoided).
