1. Not finding help here? Sign up for a free 30min 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!

First Principles-( ε-δ methods) proof.

  1. Dec 14, 2011 #1
    (X^2+1)/(X^3-9) → -1/4 as x → 1

    (without using algebra of limits. Also constructing δ explicitly).

    I have attempted this question but to no avail,

    I start like this:

    = |(X^2+1)/(X^3-9)+1/4|

    = (4(X^2+1)+X^3-9)/ 4(X^3-36)

    try factorisation but am unsuccessful.

    Anybody lend a helping hand?
     
  2. jcsd
  3. Dec 14, 2011 #2

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Expand (multiply out) the terms in the numerator. Then collect like terms and factor the result.

    That's a start.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: First Principles-( ε-δ methods) proof.
Loading...