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

Pi values

  1. Jul 28, 2004 #1
    My dad and I got in an argument about accuracy of pi values. He said that the ratio 22/7 will always be more accurate than any decimal value of pi. I said that the value 3.14159265358979 is much more accurate. I'm 100% certain that I am correct, but I can't really think of how to prove this to him. I'd also like to know how those values are measured, exactly. Thank you for your time.
     
  2. jcsd
  3. Jul 28, 2004 #2

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    22/7 is an approximation to pi. It's not even accurate to three digits.

    - Warren
     
  4. Jul 28, 2004 #3

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

  5. Jul 28, 2004 #4

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    22/7= 3.142857143. As chroot said, not even to three digits.

    (It is, however, the best approximate fraction with no more than 2 digits in the numerator.)
     
  6. Jul 28, 2004 #5
    To actually answer your question, you are looking for a proof of the irrationality of Pi. One such proof is here. Google for "irrational pi proof" to see more.

    Of course, in this context, the best "proof" would probably be to show him a calculator, press the Pi key, and then enter 22/7 for contrast.
     
  7. Jul 28, 2004 #6
    thanks for the help, all... :approve:
     
  8. Aug 2, 2004 #7
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Pi values
  1. Value of Pi calculation (Replies: 11)

  2. Why is Pi, Pi (Replies: 20)

Loading...