題目 Problem When 2x2−4xy+5y2=12x^2-4xy+5y^2=12x2−4xy+5y2=1, f(x,y)=x2+y2f(x,y)=x^2+y^2f(x,y)=x2+y2, determine the maximum value and minimum value of f(x,y)f(x,y)f(x,y). (10%)(10\%)(10%) 解答
