.如果M,N是两个不相等的实数,且满足M2-2M=1,N2-2N=1,那么代数式2M2+4N2-4N+1994=?
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![.如果M,N是两个不相等的实数,且满足M2-2M=1,N2-2N=1,那么代数式2M2+4N2-4N+1994=?](/uploads/image/z/2567112-24-2.jpg?t=.%E5%A6%82%E6%9E%9CM%2CN%E6%98%AF%E4%B8%A4%E4%B8%AA%E4%B8%8D%E7%9B%B8%E7%AD%89%E7%9A%84%E5%AE%9E%E6%95%B0%2C%E4%B8%94%E6%BB%A1%E8%B6%B3M2-2M%3D1%2CN2-2N%3D1%2C%E9%82%A3%E4%B9%88%E4%BB%A3%E6%95%B0%E5%BC%8F2M2%2B4N2-4N%2B1994%3D%3F)
.如果M,N是两个不相等的实数,且满足M2-2M=1,N2-2N=1,那么代数式2M2+4N2-4N+1994=?
.如果M,N是两个不相等的实数,且满足M2-2M=1,N2-2N=1,那么代数式2M2+4N2-4N+1994=?
.如果M,N是两个不相等的实数,且满足M2-2M=1,N2-2N=1,那么代数式2M2+4N2-4N+1994=?
M,N是方程x²-2x-1=0的两个根.
x²-2x=1
x²-2x+1=2
(x-1)²=2
x-1=±√2
x=1±√2
2M2+4N2-4N+1994
=4N2-4N+1+2M2+1993
=(2N-1)²+2M2+1993
当N=1+√2,M=1-√2时
=(2+2√2-1)²+2(1-√2)²+1993
=(1+2√2)²+2(1-2√2+2)+1993
=(1+4√2+8)+2(3-2√2)+1993
=9+4√2+6-4√2+1993
=15+1993
=2008
当N=1-√2,M=1+√2时
=(2-2√2-1)²+2(1+√2)²+1993
=(1-2√2)²+2(1+2√2+2)+1993
=(1-4√2+8)+2(3+2√2)+1993
=9-4√2+6+4√2+1993
=15+1993
=2008
你好
1.如果M,N是两个不相等的实数,且满足M2-2M=1,N2-2N=1,那么代数式2M2+4N2-4N+1994=?(过程)
由m,n是两个不相等的实数,
且满足m2-2m=1,
n2-2n=1,
可知m,n是x2-2x-1=0两个不相等的实数根。
则m+n=2,
又m2=2m+1,
n2=2n+1
2M2+4N2-4...
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你好
1.如果M,N是两个不相等的实数,且满足M2-2M=1,N2-2N=1,那么代数式2M2+4N2-4N+1994=?(过程)
由m,n是两个不相等的实数,
且满足m2-2m=1,
n2-2n=1,
可知m,n是x2-2x-1=0两个不相等的实数根。
则m+n=2,
又m2=2m+1,
n2=2n+1
2M2+4N2-4N+1994
=2(2M+1)+4(2N+1)-4N+1994
=4M+2+8N+4-4N+1994
=4(M+N)+2000
=4*2+2000
=2008
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