A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Nick88888888

  • one year ago

f(x) = 10-x and g(x) = 5x+6 , find the following: a) f(g(x)) b) g(f(x)) c) f(f(x))

  • This Question is Closed
  1. Nick88888888
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Just giving me an example of a) Is fine too im just trying to figure out how to set it up and solve it ^^

  2. DebbieG
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    f(g(x)) means to simply put the expression, g(x), into f(x) in place of all instances of the variable x. Think of it like a search-and-replace, where every x in the "outer function" (in this case, f(x)) is replaced by the inner function, in this case (5x + 6). So you get f(g(x)) = 10 - (5x + 6) = 4 - 5x Now can you try the other 2?

  3. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    f(g(x)) just applies you put the function g(x) where ever there is an x in f(x). So, \[f(g(x)) = 10-(5x+6)\] do so similarly with others.

  4. Nick88888888
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @DebbieG Ok so you got 4 - 5x by 10 - 6 and 5x being by it self? so b) would be 5(10 - x) + 6 = 50x + 6 ?

  5. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Your distribution is wrong, but yet you get the point :)

  6. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yes*

  7. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    \[g(f(x)) = 5(10-x)+6 \implies 50-5x+6\]

  8. DebbieG
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Yes, 5(10 - x) + 6, but 5(10 - x) + 6 != 50x + 6 I don't really understand what you mean by, "Ok so you got 4 - 5x by 10 - 6 and 5x being by it self?"

  9. Nick88888888
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @DebbieG I was trying to see if i understood how you did it with my way of explaining how i took what you did. If that clears it up

  10. Nick88888888
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @Astrophysics Ok so would that mean f(f(x)) 10 - (10 - x) = 10 - 10x?

  11. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    \[f(f(x)) = 10 - (10-x)\]

  12. Nick88888888
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @Astrophysics Thank you so much ^^ That was easier then i thought lol

  13. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Note that there is a "negative 1" there

  14. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    |dw:1434883474751:dw|

  15. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Np :P

  16. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    there is another notation for these problems a) f(g(x)) <--- the same as f o g b) g(f(x)) <--- the same as g o f c) f(f(x)) <--- the same as f o f Looks like more textbooks are starting to get rid of the letter circle letter notation

  17. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Ah yes, when I was learning this, we had to do it both ways

  18. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    I think it may have confused people, because it was written as such f o g (x)

  19. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I had to read right to left when I had that in my textbook

  20. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    mine was strictly the letter o letter notation

  21. Astrophysics
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    xD Yeah, it was tricky at first

  22. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.