x,y为实数,且x²+(y²/2)+4≤xy+2y,则x,y的值分别等于?
问题描述:
x,y为实数,且x²+(y²/2)+4≤xy+2y,则x,y的值分别等于?
x,y为实数,且x²+(y²/2)+4≤xy+2y,则x,y的值分别等于?
答
x²+(y²/2)+4≤xy+2y
x²+(y²/2)+4-xy-2y≤0
(x²-xy+¼y²)+(¼y²-2y+4)≤0
(x-½y)²+(½y-2)²≤0
∵(x-½y﹚²≥0,﹙½y-2﹚²≥0
∴x-½y=0,½y-2=0
y=4,x=2