Question

U=1-A/(A+B) ,A,B均等于（或趋向于）0,等于几?等于零还是等于一.

Answer 1

U=1-A/(A+B) =1-1/(1+B/A)

U=1-A/(A+B) ,A,B均等于（或趋向于）0,等于几,要看A,B趋向于0,要看B/A趋向什么,若B/A趋向0,则U=0；若B/A趋向∞,U=1；若B/A趋向于常数a,则U=1-1/(1+a).