GOD DAMN YOU ALL ARE FUCKING STUPID
WHY DOES THIS THREAD REAPPEAR EVERY FEW DAYS
.999~ = 1 EXACTLY
PROOF:
let x = .999~ (where ~ indicates repeating forever)
multiply each side by 10
10x = 9.999~
subtract x from each side
9x = 9 (because x = .999~, so we subtracted .999~ from 9.999~)
divide both sides by 9
x = 1
and we started by saying x = .999~, so...