"0,99999... é exatamente igual a 1" Onde você viu isso? 1 = 1,000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000‎

Claro que é: ache a geratriz da dízima periódica. Não estou me referindo a 0,9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999 mas a 0,999... (com infinitas casas decimais - o que é indicado pelas reticências - sem elas, não é igual a 1).