题目内容
(本题满分6分)先化简,再求值:,其中
.
解:原式= ·
····················1分
= ·
························2分
= ······························4分
当=
﹣1时,原式=
=
=
·············6分
解析:略

练习册系列答案
相关题目
题目内容
(本题满分6分)先化简,再求值:,其中
.
解:原式= ·
····················1分
= ·
························2分
= ······························4分
当=
﹣1时,原式=
=
=
·············6分
解析:略