→ yyc1217:就對集合裡的元素證明等價關係成立的三要件呀~ 01/09 00:12
→ SiriusCloud:我看不太懂 題意的集合 = = a 01/09 00:21
[100中央資工]
Determine which of the following relations (~) define equivalence
relations on the set A.
a)A is the set of all triangles in the plane ;for a,b屬於A,
a ~ b if and only if a and b are congruent.
b)A is the set of all circles in the plane; for a,b 屬於A,
a ~ b if and only if a and b have the same center.
c)A is the set of all straight lines in the plane ; for a ,b 屬於A,
a ~ b if and only if a is parrallel to b.
d)A is the set of all lines in the plane ; for a,b 屬於 A,
a ~ b if and only if a is perpendicular to b.
e)A if the set of points different from the origin in the
Euclidean plane, for a,b 屬於A , a ~ b if a = b or the
line through the distinct points a and b passes through the origin.
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答案是 T T T F T
不太懂這些選項在說明什麼 要怎麼理解呢？
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