let y=1/xlim(x->∞) x(e^(1/x) -1)=lim(y->0) (1/y)(e^y -1)y->0e^y ~ 1+ylim(x->∞) x(e^(1/x) -1)=lim(y->0) (1/y)(e^y -1)=lim(y->0) (1/y)y=1
