Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Mathematica issue

  1. Jun 5, 2008 #1
    [SOLVED] mathematica issue

    This is from Mathematica 6.0. Is this a bug in Mathematica? Supposedly the second output is precise to 100 digits!

     
    Last edited: Jun 5, 2008
  2. jcsd
  3. Jun 5, 2008 #2

    FredGarvin

    User Avatar
    Science Advisor

    I think you are running into a machine precision issue with the way your equation is entered. Take a look in the help files in 3.1.6.

     
  4. Jun 5, 2008 #3
    Hmmm...I thought the N[ ] function caused the expression to be evaluated in arbitrary precision mode. How can I get that expression in arbitrary precision mode?
     
  5. Jun 6, 2008 #4

    alphysicist

    User Avatar
    Homework Helper

    Hi ehrenfest,

    I believe the problem occurs when you give the value to x; at that point machine precision is used for x which carries over to the rest of the calculation. If you want 100 digits in arbitrary precision, you could use:

    x=0.00004`100

    and then calculate

    N[(1 + x)^(1/3) - 1 - x/3 + (x^2)/9 - 5 (x^3)/81, 100]
     
  6. Jun 6, 2008 #5
    problem solved!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Mathematica issue
Loading...