Sunday, November 7, 2010

Two algebraic proofs that 0.99999.....=1

Proof 1:

1/9=0.111.......
9 x 1/9 =0.9999......
1=0.999........

Proof 2 :


Let x=0.999999......
10x=9.99999.......
10x-x=9
9x=9
x=1