Solve f(g(3)) - Get Guidance & Help Now

[lakitu]

hey i am trying to figure out this equation, don't know where to start with it? Would anyone be able to give me any guidence ?

If f(x) = 2 x - 4 and g(x) = x² - x - 4, work out f(g(3)).


Any help would be great

Thank you

 

[QueenFisher]

the way i do it is:

x=3
so looking at your g(x) equation, every time you see an x, substitute in 3 and see what you get. then do the same with the answer of g(x), by putting the answer into f(x) every time you see an x and then doing the arithmetic.

hope that helps

 

[Markjdb]

So an actual solution would be:

g(3) = (3)^2 - 3 - 4
g(3) = 2
f(g(3)) = f(2)
f(2) = 2(2) - 4
f(2) = 0
f(g(3)) = 0

 

[z-component]

Please don't show full solutions, but rather guide the original poster through to arrive at his/her own solution.

 

[Markjdb]

Please don't show full solutions, but rather guide the original poster through to arrive at his/her own solution.

My apologies.

 

[lakitu]

thank you for your posts, i understand now :)

lakitu