題目 Problem 乙、計算、證明題:共 3 題,每題 12 分,共 36 分。須詳細寫出計算及證明過程,否則不予計分。 Find any extrema of the function f(x,y)=e−xy/4f(x,y)=e^{-xy/4}f(x,y)=e−xy/4 subject to the constraint x2+y2≤1x^2+y^2\le 1x2+y2≤1. 解答