已知m,n是实数,且满足m2+2n2+m- n+ =0,则-mn2的平方根是( )输入错误、应为:m^2+2n^2+m-4/3n+17/36=0,则-mn2的平方根是
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![已知m,n是实数,且满足m2+2n2+m- n+ =0,则-mn2的平方根是( )输入错误、应为:m^2+2n^2+m-4/3n+17/36=0,则-mn2的平方根是](/uploads/image/z/12550438-46-8.jpg?t=%E5%B7%B2%E7%9F%A5m%2Cn%E6%98%AF%E5%AE%9E%E6%95%B0%2C%E4%B8%94%E6%BB%A1%E8%B6%B3m2%EF%BC%8B2n2%EF%BC%8Bm%EF%BC%8D+n%EF%BC%8B+%EF%BC%9D0%2C%E5%88%99%EF%BC%8Dmn2%E7%9A%84%E5%B9%B3%E6%96%B9%E6%A0%B9%E6%98%AF%EF%BC%88+%EF%BC%89%E8%BE%93%E5%85%A5%E9%94%99%E8%AF%AF%E3%80%81%E5%BA%94%E4%B8%BA%EF%BC%9Am%5E2%2B2n%5E2%2Bm-4%2F3n%2B17%2F36%3D0%EF%BC%8C%E5%88%99%EF%BC%8Dmn2%E7%9A%84%E5%B9%B3%E6%96%B9%E6%A0%B9%E6%98%AF)
已知m,n是实数,且满足m2+2n2+m- n+ =0,则-mn2的平方根是( )输入错误、应为:m^2+2n^2+m-4/3n+17/36=0,则-mn2的平方根是
已知m,n是实数,且满足m2+2n2+m- n+ =0,则-mn2的平方根是( )
输入错误、应为:m^2+2n^2+m-4/3n+17/36=0,则-mn2的平方根是
已知m,n是实数,且满足m2+2n2+m- n+ =0,则-mn2的平方根是( )输入错误、应为:m^2+2n^2+m-4/3n+17/36=0,则-mn2的平方根是
用配方法求解
原式即:m^2+m+1/4+2(n^2-2/3n+1/9=(m+1/2)^2+2(n-1/3)^2=0,
得m=-1/2,n=1/3,-mn^2=1/18,平方根是1/6√2.
m^2+2n^2+m-4/3n+17/36=0
(m^2+m+1/4)+2(n^2-2/3n+1/9)=0
(m+1/2)^2+2(n-1/3)^2=0
平方大于等于0,相加等于0,若有一个大于0,则另一个小于0,不成立。
所以两个都等于0
所以m+1/2=0,n-1/3=0
m=-1/2,n=1/3
-mn^2=-(-1/2)*(1/3)^...
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m^2+2n^2+m-4/3n+17/36=0
(m^2+m+1/4)+2(n^2-2/3n+1/9)=0
(m+1/2)^2+2(n-1/3)^2=0
平方大于等于0,相加等于0,若有一个大于0,则另一个小于0,不成立。
所以两个都等于0
所以m+1/2=0,n-1/3=0
m=-1/2,n=1/3
-mn^2=-(-1/2)*(1/3)^2=(1/2)*(1/9)=1/18
收起
题都搞忘了,是不是高中的题哦,具体的公式记不到了,你如果翻下书看下公式应该还是比较好做的,我刚做了就是忘了一个公式,你再试下?
m^2+2n^2+m-4/3n+17/36=0
(m^2+m+1/4)+2(n^2-2/3n+1/9)=0
(m+1/2)^2+2(n-1/3)^2=0
得:m=-1/2 n=1/3 -mn^2=-(-1/2)*(1/3)^2=(1/2)*(1/9)=1/18
最终的平方根为√2/6