(1+(1/n))^n < e < (1+(1/n))^(n+1)
Donc en enlevant (1+(1/n))^n on obtient :
e - (1+(1/n))^n < (1+(1/n))^(n+1) - (1+(1/n))^n
(1+(1/n))^(n+1) - (1+(1/n))^n = ((1+(1/n))^n)(1+(1/n)-1) = ((1+(1/n))^n)/n
Or (1+(1/n))^n < e < 3,
donc e - (1+(1/n))^n < 3/n.