1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Stuck Again : -->

  1. Jun 28, 2016 #1
    science1.PNG I was doin' some coursera quiz. It asked this question :
    Let ƒ(x) = (x2 - x - 42) / x-7
    find as x → 7.
    Now I approach x from both sides and it get me 2 different answer.
    So which one is correct:
    13 or 14?
     
  2. jcsd
  3. Jun 28, 2016 #2

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Please post your working.
     
  4. Jun 28, 2016 #3

    SteamKing

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Also, please try to post your HW threads in the appropriate HW forum by topic.
     
  5. Jun 28, 2016 #4

    symbolipoint

    User Avatar
    Homework Helper
    Education Advisor
    Gold Member

    Note that simplifying f will give the LINE y=x+6, and the FUNCTION is undefined for x=7. The limit at x=7 is that missing point. You just need to set x=7 for y=x+6.
     
  6. Jun 28, 2016 #5
    OK get It.
     
  7. Jun 28, 2016 #6

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    The function is not ##f(x) = \frac{x^2-x-42}{x} -7##, as you wrote.
     
  8. Jul 6, 2016 #7
    Yes it must be like ƒ(x) = (x2 - x - 42) / (x-7).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Stuck Again : -->
  1. Limits again (Replies: 12)

  2. Polars again (Replies: 1)

  3. Limits again (Replies: 5)

  4. Trig. again (Replies: 3)

  5. Connectedness again (Replies: 8)

Loading...