uv满足v=根号下{(2u
u,v满足v=根号下{(2u-v)/(2u 3v)} 根号下{(v-2u)/(4u 3v)} 2/3,求u^2-uv的值
根号下[(2u-v)/(2u+3v)]>=0;& 根号下[(v-2u)/(4u+3v)]>=0;& 2/3>0. --->v>0 (2u-v)/(2u+3v)>=0--->u=v/2. (v-2u)/(4u+3v)>=0--->-3v/4u=v/2--->2u-v=0;& v-2u=0 --->v=0+0+2/3=2/3:& u=v/2=1/3 --->u^2-uv=(1/3)^2-1/3*2/3=-1/9
答:解:此题是全国奥林匹克"初中竞赛练习卷"初二练习卷中题. ∵(2u-v)/(4u+3v)≥0 (u-2v)/(4u+3v)≥0 ∴(2u-v)/(4u+3...详情>>
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