Answer:
[tex]f(x) = {x}^{2} - 6x + 9[/tex]
Step-by-step explanation:
If f(x) = (tt)(x), that's essentially squaring t(x) so
[tex]f(x) = {t(x)}^2 \\ f(x) = (-x +3)^2 \\ f(x) = (-x +3)(-x +3) \\ f(x) = -x(-x +3) +3(-x +3)\\ f(x) = x^2 -3x -3x +9 \\ f(x) = x^2 -6x +9[/tex]
