Step-by-step explanation:
For this composition function, [tex]f(g(x))[/tex], we should substitute [tex]g(x)[/tex] anytime we see an [tex]x[/tex] variable in [tex]f(x)[/tex]:
[tex]x^{2} + 1[/tex]
[tex][g(x)]^{2} + 1[/tex]
[tex](3x)^{2} + 1[/tex]
[tex]9x^{2} + 1[/tex]
