题目内容
已知w、x、y、z四个数都不等于0,也互不相等,如果w+
=x+
=y+
=z+
,那么w2x2y2z2= .
| 1 |
| x |
| 1 |
| y |
| 1 |
| z |
| 1 |
| w |
考点:对称式和轮换对称式
专题:
分析:先根据w+
=x+
=y+
=z+
分别表示出w-x,x-y,y-z,z-w的值,再把这四个式子进行相乘,即可求出w2x2y2z2的值.
| 1 |
| x |
| 1 |
| y |
| 1 |
| z |
| 1 |
| w |
解答:解:∵w+
=x+
,
∴w-x=
-
=
,
同理可得:
x-y=
-
=
,
y-z=
,
z-w=
,
∴(w-x)(x-y)(y-z)(z-w)=
•
•
•
=
∴w2x2y2z2=1.
故答案为:1.
| 1 |
| x |
| 1 |
| y |
∴w-x=
| 1 |
| y |
| 1 |
| x |
| x-y |
| xy |
同理可得:
x-y=
| 1 |
| z |
| 1 |
| y |
| y-z |
| yz |
y-z=
| z-w |
| zw |
z-w=
| w-x |
| wx |
∴(w-x)(x-y)(y-z)(z-w)=
| x-y |
| xy |
| y-z |
| yz |
| z-w |
| zw |
| w-x |
| wx |
| (x-y)(y-z)(z-w)(w-x) |
| w2x2y2z2 |
∴w2x2y2z2=1.
故答案为:1.
点评:此题考查了对称式和轮换对称式;解题的关键是通过变形得出(w-x)(x-y)(y-z)(z-w)=
.
| (x-y)(y-z)(z-w)(w-x) |
| w2x2y2z2 |
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