For this case we have the following functions:
[tex]f (x) = 7x + 1\\g (x) = x ^ 2[/tex]
We must find[tex](g_ {0} f) (x).[/tex]
By definition of composition of functions we have to:
[tex](g_ {0} f) (x) = g (f (x))[/tex]
So:
[tex](g_ {0} f) (x) = g (f (x)) = (7x + 1) ^ 2 = 49x ^ 2 + 2 (7x) (1) + 1 = 49x ^ 2 + 14x + 1[/tex]
ANswer:
[tex](7x + 1) ^ 2 = 49x ^ 2 + 14x + 1[/tex]