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

Why 0!=1

  1. Jul 6, 2013 #1
    the explanation i got for this is because..

    (x+1)!=(x+1)x!

    and that when x=0

    (0+1)!=(0+1)0!

    simplified 1=0!

    but this implies (0+1)!=1... i don't see how....... if (0+1)0!=0!, then for (0+1)!=1, where did the factorial symbol go? why does the factorial disappear for this? (0+1)!=(0+1)(0)(0-1)(0-2)etc... so someone please explain to me why (0+1)!=1
     
  2. jcsd
  3. Jul 6, 2013 #2

    micromass

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    We have that ##0+1=1##, thus ##(0+1)! = 1! = 1##.
     
  4. Jul 6, 2013 #3

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    The factorial sumbol vanished on the RHS because the factorial was evaluated.

    (0+1)0! = (0+1)!
    => 1x0! = 1!
    => 0! = 1
     
  5. Jul 6, 2013 #4

    jedishrfu

    Staff: Mentor

  6. Jul 7, 2013 #5

    symbolipoint

    User Avatar
    Homework Helper
    Education Advisor
    Gold Member


    That video is perfect. That is the best explanation I ever saw. The guy simply followed the pattern.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Why 0!=1
  1. Why 0^0 = 1 (Replies: 15)

  2. Why is it that 0! = 1? (Replies: 16)

  3. Question : Why 0! = 1 ? (Replies: 11)

  4. Why is 0! = 1? (Replies: 8)

  5. Why n^0=1? (Replies: 4)

Loading...