Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

kirk.freedman Group Title

Let f(x) = (x^2 + 3x – 4) and g(x) = (x + 4). a. Find f • g and state the domain. b. Find f/g and state the domain.

  • one year ago
  • one year ago

  • This Question is Closed
  1. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    So I know I start by multiplying (x^2+3x-4)(x+4)... I get x^3+7x^2+8x-16 what now?

    • one year ago
  2. sparik1997 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    f • g=x^3+4x^2+3x^2+12x-4x-16=x^3+7x^2+8x-16 the domain means what values can x get, here, x can be any real number. so the domain is all numbers.

    • one year ago
  3. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    How do I know it is all numbers and there isn't like one number that doesn't work? Is there a way to check that?

    • one year ago
  4. sparik1997 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    f/g=(x^2 + 3x – 4)/(x+4) as we know, the denominator can't be equal to 0, so x+4 can't be equal to 0, that means, x can be any number but -4

    • one year ago
  5. sparik1997 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    if there is a square root or a denominator, you must consider that denominator can't be 0 and the expression in the square root is >=0

    • one year ago
  6. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Wait so what is f/g?

    • one year ago
  7. sparik1997 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    the domain of f/g is any real number but -4

    • one year ago
  8. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Yeah, that's the domain, but it says find f/g and then it says also find the domain, I thought that that means I need two answers there?

    • one year ago
  9. sparik1997 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    f/g=(x^2 + 3x – 4)/(x+4)

    • one year ago
  10. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    wait, what would be the steps to find that the domain of f/g is all but -4?

    • one year ago
  11. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    is it like x+4>=0 then subtract 4 from both sides so you have x>=-4?

    • one year ago
  12. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    thanks!

    • one year ago
  13. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1356492631732:dw| now what @Hero

    • one year ago
  14. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Oh yeah, I knew that xD thanks! so it's x-1?

    • one year ago
  15. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    And i'm done now?

    • one year ago
  16. kirk.freedman Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Thanks to both of you!

    • one year ago
    • Attachments:

See more questions >>>

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.