数学问题2！

mitmydreamUID: 2113494

1）发生函数generating fucntion是什么概念！
2）the factor group(Z2*Z3)/<(1,0)>has order 3.why?该题出自REA-3-17
3）Find the join of the subgroups<4>and <6>of Z12 ,the answer is <2>.
    bur i cannot understand, 该题出自Rea-3-23
4)if F is a finite field, then which of the following numbers can be the cardinality of F?
   the answer is 27.REA-3-59

huangjin_suzhouUID: 37183

1 don't remember the definition le,sigh,but remerber one point:generate function is a kind of function which can be used to determine the coefficients of the power series.
2 should be 6, if you mean direct sum
3  I cann't see your problem,but if Z12 means multiplication group, not the Z12, which 12 is the subscript, then it can be correct
4 it is clear as it must be a cubic number to make the equivalance stands in field.

[ Last edited by huangjin_suzhou on 2005-10-30 at 11:48 ]

nikcxUID: 199472

1.密级数做发生函数时，其系数就是你要的数列，具体细节你可以去看看发生函数论
2.factor group 就是商群，<(1,0)>生成2阶子群，6/2=3
3.join of subgroup 就是包含这两个子群的最小子群
4.不是很明白，希望有人解答一下

chrjoyUID: 2132101

有限域都是p的幂次型的。

nikcxUID: 199472

Zp是有限域等价于p是素数或素数次幂，是么？

chrjoyUID: 2132101

是的。