Question

Express your answer as a polynomial in standard form.
f(x) = 3x² + 5x + 13
g(x) = x - 3
Find: (fog)(x)

Answer 1

$(f\circ g)(x)=f(g(x))=f(x-3) \\ \\ =3(x-3)^2+5(x-3)+13 \\ \\ =3(x^2 -6x+9)+5(x-3)+13 \\ \\ =3x^2 -18x+27+5x-15+13 \\ \\ =\boxed{3x^2 - 13x +25}$