Prove that 3.999... = 4
I don't think you can use Tristan's proof. If 3.999... equals 4, then 4.0000...001 must equal 4 as well. So 3.999... then equals 4.000...001. But these can't be the same since 4.0 is a number between these.
I don't think you can actually prove 3.999... equals 4. Mathematically the posted solution is correct, but literarily 3.999... is equal to "almost 4". And almost only counts in...
...horseshoes and grenades
