Forgot your password?
typodupeerror
Math

Quantum Jim's Journal: My /. fortune is mistaken 4

Journal by Quantum Jim

My /. fortune was:

(1) X=Y ; Given
(2) X^2=XY ; Multiply both sides by X
(3) X^2-Y^2=XY-Y^2 ; Subtract Y^2 from both sides
(4) (X+Y)(X-Y)=Y(X-Y) ; Factor
(5) X+Y=Y ; Cancel out (X-Y) term
(6) 2Y=Y ; Substitute X for Y, by equation 1
(7) 2=1 ; Divide both sides by Y
-- "Omni", proof that 2 equals 1

However, you can only cancel out the (X-Y) if X != Y because if they are equal then the expression is zero! Indeed, the rest of the steps can be left, so you end up with:

2(x-y) = (x-y)
0 = 0

Friends don't let friends divide by zero!

This discussion has been archived. No new comments can be posted.

My /. fortune is mistaken

Comments Filter:
  • long time no see... how's the BJJ going?
    • Hey, BJJ is going good. I got promoted to blue, won a few tournaments, and am half way to purple I think. How's the krav maga going along? I have been pretty busy and haven't been around for a while. Hopefully I have some more free time now...
      • by tuxette (731067) *
        Sounds great! Krav Maga is going fine, except I have this finger injury that is really cramping my style :-( I hope it's better in time for grading in June...
        • Good luck with your grading. I always buddy-tape injured fingers and toes. Even when not training, the buddy tape helps it heal faster.

Anyone can do any amount of work provided it isn't the work he is supposed to be doing at the moment. -- Robert Benchley

Working...