已知X^2=x+1,y^2=y+1,且x≠y.1.求证x+y=1;2.求x^5+y^5的值

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已知X^2=x+1,y^2=y+1,且x≠y.1.求证x+y=1;2.求x^5+y^5的值
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已知X^2=x+1,y^2=y+1,且x≠y.1.求证x+y=1;2.求x^5+y^5的值
已知X^2=x+1,y^2=y+1,且x≠y.1.求证x+y=1;2.求x^5+y^5的值

已知X^2=x+1,y^2=y+1,且x≠y.1.求证x+y=1;2.求x^5+y^5的值
1.证明:由x^2-y^2=(x+y)(x-y)
代入x^2 y^2得x+1-y-1=(x+y)(x-y)
得x-y=(x+y)(x-y)
因为x不等于y 所以 x+y=1
2.x^5+y^5=x2x2x+y2y2y
把x2 y2入
上式得x(x+1)^2+y(y+1)^2
(x+1)^2 (y+1)^2展开继续代入
得2+3(x^2+y^2)
继续展x2 y2代入得 2+3(x+y+2)=2+3*3=11