天气预报 > 财经 > 一次除以二次的最值怎么求
一次除以二次的最值怎么求
更新时间: 2021-04-10 13:23:40  

可以利用换元法,把它化作一元二次方程,再求最值

例如f(t)=(-1-t)/t2求最值

原式=-(1/t2+1/t)

令1/t=x,则x属于(负无穷,0)并上(0,正无穷)

所以原式=-x2-x= -(x2+x)=—(x+1/2)2+1/4

所以当x=-1/2时,即t=-2时,原式取最大值1/4

要注意换元后,变量的取值范围的变化

关键词: 除以 怎么

一次除以二次的最值怎么求相关经验

天气预报

最新推荐

页面:/news/view-2611116/ | 耗时:0.3721 s | 内存:2.11 MB | 查询:4 | 缓存读取:3 写入:0 | 加载文件:25
select * from tbl_Articles WHERE ArticleID=2611116 LIMIT 0,1
select * from tbl_Articles_data WHERE ArticleID=2611116 LIMIT 0,1
select * from tbl_Articles_sphinx where id=2611116 LIMIT 0,1
SELECT ArticleID,Title FROM tbl_Articles WHERE ArticleID IN(701501,972452,597654,558219,903678,1624965,1793788,2932182,520405,3488686,551174,1137844,669871,1017680,522700,3524489,1628555,488731,1180701,1156049,797408,1609968,1144331,694524,695511,2055126,730920,1642585,948072,889729) ORDER BY field (ArticleID,701501,972452,597654,558219,903678,1624965,1793788,2932182,520405,3488686,551174,1137844,669871,1017680,522700,3524489,1628555,488731,1180701,1156049,797408,1609968,1144331,694524,695511,2055126,730920,1642585,948072,889729)