A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

help please :) What is the domain and range of (4x+3)/x^2-1

  • This Question is Closed
  1. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    the domain is all real numbers but -1 and 1 right??

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

    yeah since there is a fraction. we have a restriction so \[(x^2-1) =(x+1)(x-1) \] x=1, -1 so our domain should be all reals except when x =-1 or x = 1. Those restrictions create a blank space in the graph

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

    what about range?

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

    range is in the y-axis... hmm.

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

    range is always a pain >_< but here's the graph of the function

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

    i don't get it :/

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

    we have the domain... which x is all reals except when x =1 and x =-1

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

    we got the graph of the function ... the range is in the y-axis so it must be all reals except when y is some number ?!

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

    @jim_thompson5910 I need to refresh my memory. Range is in the y-axis but how do we find it again when there are restrictions in the function ?

  10. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    degree of denominator = 2 degree of numerator = 1 since (degree of denominator) > (degree of numerator), this means y = 0 is a horizontal asymptote. So y = 0 would be kicked out of the range but y = 0 is certainly possible. Just let x = -3/4

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

    ?!

  12. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    plug in x = -3/4 and you'll get y = 0

  13. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so the range is the set of all real numbers

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

    how is the range all reals? I don't get that part..

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

    oh wait.. unless the line is going through all y -values. ._.

  16. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah any y value is possible

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

    wait i don't get it

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

    it is all reals XD . My mind went blank . Why is domain easier to find than range?

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

    in the graph the lines is going through all the y-values where as in the x-values, there is a break (like an empty space) at x=1, x = -1

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

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

    oh!! i see it, thank you :) can you also help me on finding the relative extrema for 2x^3+5x^2-25x?

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

    alright but first we have to graph this

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

    can we find it without graphing

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

    relative extrema.. like maxs and mins.. (gonna be hard though without a graph )

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

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

    there's the first derivative test though for increasing and decreasing.. finding extremas... but I'm not sure if you're at that level yet.

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

    nope haha im confused. i'm supposed to find it without equation i think

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

    without the graph*

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

    so you're not in a calculus course?

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

    its precalc!

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

    ok... do you know how to take derivatives?

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

    weird you need those

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

    this site has an example for finding relative extrema http://ltcconline.net/greenl/courses/105/theoremsrelatedrates/extrema.htm

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

    i figured it out haha thanks :)

  35. 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.