Combining functions

[sunshinedaydream]

I have no idea how to combine functions. Any explanation and/or help would be appreciated. Thanks!

1. Given f=x^2-4x-2
g=x+7

find (fxg)(x)

2. Given: f(x) = 1/x-2
g(x) = 4/x Find
(gof) (x)=
(fog)(x)=

3.
Using the previous function find
(fog)(3)=


Once again, any help or explanation is appreciated. Thank you!

 

[stapel]

You say that you "have no idea how to combine functions". Does that mean that you are requesting lessons on function operations and compositions?

Also:

1) Is "(fxg)(x)" meant to be "(fg)(x)", or is the extra "x" meant to indicate "f(x) times x times g(x)"?

2) Is f(x) "(1/x) - 2", as written, or did you mean "1/(x - 2)"?

3) Plug 3 into g. Plug the result into f. Simplify.

Thank you.

Eliz.

 

[sunshinedaydream]

Hello, thanks for the reply. I have learned about combining functions unfortunately I cannot remember the information and often need a refresher.

#1. F times G

#2. 1/(x-2)

#3 I understand. Thanks again for your assistance