If x=4λ1+λ2 and y=2−2λ21+λ2 where λ is a real parameter then Z=x2−xy+y2 lies between
If x=4λ1+λ2 and y=2−2λ21+λ2 where λ is a real parameter and x2–xy+y2 lies between [a,b] then (a+b) is