Question

求函数y=(X2-X+2)/(X+1)的值域(X≠1）

Answer 1

x+1≠0,x≠-1

y=(x^2-x+2)/(x+1)

y=[x^2+x-2(x+1)+4]/(x+1)

y=[x(x+1)-2(x+1)+4]/(x+1)

y=x-2+4/(x+1)

y=(x+1)+4/(x+1)-3

x>-1时：x+1>0

y=(x+1)+4/(x+1)-3>=4-3=1,又：X≠1,∴y≠1,∴：y>1

当x