用分离常数法求y=x/x+1的值域

问题描述:

用分离常数法求y=x/x+1的值域
RT,

y=x/(x+1)
=(x+1-1)/(x+1)
=(x+1)/(x+1)-1/(x+1)
=1 - 1/(x+1)
x不等于-1即Y不等于1