Question

Let f(x) = x – 6 and g(x) = x2 – x + 4. Find g(f(x)).

x^2 – 13x + 46

x^2 – 11x + 34

x^2 – 2x – 2

x^2 – x – 2

Answer 1

so you look at your "f" function first....plug "x" in wherever you see an x...sounds pointless i know

f(x) = x-6

so now....plug that answer (x-6) into your "g" function wherever you see an x

g(x) = x2 – x + 4
g(x-6) = (x-6)² - x-6 + 4
= x² - 12x +36 -x - 6 + 4
= x² -13x + 34

Answer 2

hmmm that's not right :/ lemme check that over

Answer 3

yeah i'm not sure, i tried doing it the same way

Answer 4

oh duh..... lol

g(x-6) = (x-6)² - x-6 + 4
= x² - 12x +36 -x + 6 + 4
-12x - 1x is -13x......36..+6...+4....is 46

= x² -13x + 46

Answer 5

just remember to keep the ( ) around the (x - 6) or else you run into the same mistake I did there

so

g(x) = x2 – x + 4
g(x-6) = (x-6)² - (x-6) + 4
distribute the - sign into those parenthesis

g(x-6) = (x-6)² -x + 6 + 4
and foil out that (x-6)²

= x² - 12x +36 -x + 6 + 4
= x² -13x + 46

:)

Answer 6

see where i made the mistake? and how i fixed it?

Answer 7

Yes! thank you

Answer 8

anytime :)