Welcome to DeKalb's first AP Calculus blog page. The intent of this page is to allow you to communicate with your classmates on homework problems, or other topics in our class. I will check the page and postings every night Sunday through Thursday.

Monday, October 3, 2011

I Would Like My Bonus Points

In order to obtain my two bonus points I will post a reason why in my opinion .9 repeating is equal to 1.
In this post .9 repeating will be denoted by .9'
1 divided by 3 is 1/3
1 divided by 3 is also .3'
1/3 multiplied by 3 is 1
.3' multiplied by 3 is .9'
.3' = 1/3
3 • .3' = 3 • 1/3
After multiplying it out we arive at:
.9' = 1
There we go =D
Posted by at

5 comments:

  1. VanWizzyOctober 3, 2011 at 11:18 PM

    I personally prefer the addition proof of this idea.
    2/9 is equal to .2'
    +7/9 is equal to .7'
    =9/9 or 1 and .9'

    ReplyDelete
  2. IanOctober 4, 2011 at 9:56 AM

    @VanWizzy

    i have never seen that one before. i like it

    ReplyDelete
  3. ForrestOctober 4, 2011 at 11:43 PM

    This comment has been removed by the author.

    ReplyDelete
  4. ForrestOctober 4, 2011 at 11:44 PM

    I personally prefer the algebraic manipulation proof.

    x = .9'
    10x = 9.9'
    10x-x = 9.9'-0.9'
    9x = 9
    x = 1

    x = 0.9' = 1

    ReplyDelete
  5. VanWizzyOctober 5, 2011 at 10:40 PM

    @FW
    I like that one too

    ReplyDelete

Note: Only a member of this blog may post a comment.

Subscribe to: Post Comments (Atom)