x3+y3=2,求x+y的最大值
问题描述：
x3+y3=2,求x+y的最大值
答
先进行因式分解,得：x³+y³ =(x+y)(x²-xy+y²) =(x+y)[(x+y)²-3xy]=2···········① 由于(x-y)²≥0,展开即得：2xy≤x²+y² 4xy≤x²+2xy+y² 4xy≤(x+y)...
x3+y3=2,求x+y的最大值
先进行因式分解,得：x³+y³ =(x+y)(x²-xy+y²) =(x+y)[(x+y)²-3xy]=2···········① 由于(x-y)²≥0,展开即得：2xy≤x²+y² 4xy≤x²+2xy+y² 4xy≤(x+y)...