var ancestorid_131463='131460'; var isauth_131463='0'; var istop_131463='0'; var iselite_131463='0'; var iscommend_131463='0'; var islock_131463='0'; var title_131463='Re:数算系列 解题思路和突破口'; var body_131463='1,一大一小交替出现,首先考虑隔项数列;
2,由小到大再到小,必与指数有关;
3,注意观察是否平方/立方的变形(或者不同数的平方/立方相加/相减等);要求对以上前提篇的熟练运用
4,跳跃较大则考虑乘积/次方,跳跃较小则考虑差/二重差;
5,尝试把各数间差,及二重差列出,寻找规律;
6,尝试把各数变化成某平方式,看是否存在规律;
以上皆不可行,建议放弃

这是偶从参考书上copy的~供大家学习

PS:怎么没人来看哦
'; var body1_131463=''; var sign_131463=''; var cn_131463='lihui729@sohu'; var nickname_131463='菜鸟女侠'; var inputdate_131463='2007-11-13 15:18:31'; var mobile_131463='1'; var Upassportid_131463='lihui729@sohu.com'; var Usex_131463='2'; var Uartn_131463='747'; var Ueliten_131463='47'; var Ucommn_131463='27'; var Uloginn_131463='684'; var Ulinet_131463='7675'; var Uscore_131463='3325'; var Upower_131463='419'; var Ulevel_131463='3'; var Urole_131463='30'; var Uwenji_131463=''; var Uavatar_131463=''; var avatartype_131463=''; var avatarstr_131463='5/48'; var Uawatarkey_131463='d77ca24f';