Limits at Infinity...4

Discussion in 'Calculus' started by nycmathguy, May 28, 2022.

  1. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    Calculus
    Section 2.6

    IMG_20220527_193149.jpg
     
    nycmathguy, May 28, 2022
    #1
  2. nycmathguy

    MathLover1

    Joined:
    Jun 27, 2021
    Messages:
    2,989
    Likes Received:
    2,884
    lim(e^(1/x)) as x->0 from the left

    note: e^(1/x)= upload_2022-5-27_18-51-26.gif

    upload_2022-5-27_18-49-11.gif .....so, if x->0 we have upload_2022-5-27_18-52-37.gif

    [​IMG]

    so, left limit is zero

    but if x->0 from the right, limit is infinity

    upload_2022-5-27_18-58-43.gif

     
    MathLover1, May 28, 2022
    #2
    nycmathguy likes this.
  3. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    The sqrt{e} when the index is 0 = e^(1/0) when replacing x with 0. I thought 1/0 = undefined. No?
    The graph explains it slightly better but what you said concerning x approaching 0 is not too clear.
     
    nycmathguy, May 28, 2022
    #3
  4. nycmathguy

    MathLover1

    Joined:
    Jun 27, 2021
    Messages:
    2,989
    Likes Received:
    2,884
    upload_2022-5-28_9-31-41.gif -> right limit

    upload_2022-5-28_9-31-57.gif ->left limit

    since not equal, two-sided limit does not exist

    [​IMG]
     
    MathLover1, May 28, 2022
    #4
    nycmathguy likes this.
  5. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    If I replace x with 0 for sqrt{e}, is this not e^(1/0)?
    This means e^(undefined). I understand the graph but not what you said about sqrt{e} as x tends to 0 from the left.
     
    nycmathguy, May 28, 2022
    #5
  6. nycmathguy

    MathLover1

    Joined:
    Jun 27, 2021
    Messages:
    2,989
    Likes Received:
    2,884
    e^(1/x) is same as upload_2022-5-28_11-43-46.gif (you should know that), then observe the graph to see a left and right limit
     
    MathLover1, May 28, 2022
    #6
    nycmathguy likes this.
  7. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    I know that, Mira. As x tends to 0 from the left or right, we replace x with 0, right?

    So, sqrt{e} when x is the index leads to e^(1/x). Yes?
    If x = 0, do we or do we not get e^(1/0)? If this is true, we get e^(undefined). No?
     
    nycmathguy, May 28, 2022
    #7
  8. nycmathguy

    MathLover1

    Joined:
    Jun 27, 2021
    Messages:
    2,989
    Likes Received:
    2,884
    e^(1/x) is NOT sqrt{e} ........take a good look : it is [​IMG]
     
    MathLover1, May 28, 2022
    #8
    nycmathguy likes this.
  9. nycmathguy

    nycmathguy

    Joined:
    Jun 27, 2021
    Messages:
    5,386
    Likes Received:
    422
    The sqrt{e} = e^(1/2). No? The denominator of the exponent represents the index of the square root. No?
     
    nycmathguy, May 29, 2022
    #9
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Similar Threads
Loading...