I know there IS something like this, but right at the start your tutor's proof says "2x=x" which can't be true (unless x=0 when lots of silly things become true).

But there is this one:

Start with: a = b

Then add (-b+b) to the left hand side (this is OK because you are adding 0:      a - b + b = b

Now divide both sides by (a-b) and we have:

        a - b + b   =    b
        ________     _____
          (a-b)          (a-b)

Reducing the left side:
             
        1 +     b     =     b
               ____       _____
               (a-b)       (a-b)

Then subtract b/(a-b) from both sides and you have:

                1=0


(Mwuuhahhah - maniacal laughter!)

But before we all think that Algebra is odd, there IS a mistake in the proof.

When I first saw it I was confooosed, and someone had to point out to me that because we said that a=b, then (a-b) must equal zero. When you start multiplying or dividing by zero, all hell breaks loose, and you start to get weird looking proofs.

So watch out for those in your proofs!

That was weird. Any more like that?

I do have another......

Hi,
How   are  you  doing?
By  the  way   where   do   you   stay.
Send  me  mail  ,go  to   HELPME   and   then    you  go  to
Maths  by  ravali.
byeeeee,
ravali

I think most of us here are in the UK (well, I think, anyway).

That's because you have a thing for penguins.

I don't care. I know what I like and that's white white white.

Give us grease that makes us obese....oh how we love to eat junk!

Whatever Trevor

Actually no, you heard me saying it and put it in here before me!