Y=x/(x+1)=1-1/(x+1)定义域x+1≠0,x≠-1值域：1/（x+1）≠0y≠1y=√(x+1)定义域x+1≥0,x≥-1值域：y≥0y=x+√(2x+1)定义域2x+1≥0,x≥-1/2因为y=x和y=√(2x+1)在x≥-1/2都是增函数x=-1/2时,y=-1/2所以值域为y≥-1/2y...