[問題]我明白了
由 tangpakchiu 於 星期二 二月 20, 2007 4:30 pm
#ed_op#DIV#ed_cl##ed_op#DIV#ed_cl#p^(q-2)=(m+1)(m-1) ,(m+1,m-1)的最大公因數為1or2#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#當為2時,p為質數,即p為2,所以m+1,m-1一定要為2次方的幕,#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#易知m=3--->q=5#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#所以(p,q,r)=(2,5,2),(2,2,5)#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#當為1時,m+1和m-1為奇數,但p為質數,所以m=2,即p=3,q=3#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#所以(p,q,r)=(3,2,3),(3,3,2)#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#質數有無限多個???~~~~#ed_op#/DIV#ed_cl##ed_op#/DIV#ed_cl#