Forgot password
 Register account
View 2113|Reply 6

[函数] 正确答案究竟是哪个

[Copy link]

167

Threads

381

Posts

5

Reputation

Show all posts

lrh2006 posted 2015-5-19 15:43 |Read mode
当且仅当x∈(a,b)∪(c,+∞)(其中b<=c)时,函数f(x)=2|x+1|的图像在函数g(x)=|2x-t|+x图像的下方,则c+b-a的取值范围为?参考答案是(1,+∞),我算出来是(-4/3,+∞),请大家帮我看看正确答案究竟是哪个,谢谢!
活着&存在 posted 2015-5-19 17:21
未命名.JPG

167

Threads

381

Posts

5

Reputation

Show all posts

original poster lrh2006 posted 2015-5-19 18:13
回复 2# 活着&存在


    t为什么大于-1?难道不是t/2>-1,t>-2吗?我其余的跟你都一样

167

Threads

381

Posts

5

Reputation

Show all posts

original poster lrh2006 posted 2015-5-19 23:14
回复 2# 活着&存在


    在吗?可否解释下,谢谢!
活着&存在 posted 2015-5-19 23:46
过A且斜率为-1的直线,与X轴的交点的横坐标为t>-1

209

Threads

949

Posts

2

Reputation

Show all posts

敬畏数学 posted 2015-5-20 12:53
回复 1# lrh2006
等价:2|x+1|-x<|2x-t|,当且仅当x∈(a,b)∪(c,+∞)(其中b<=c)时成立。

167

Threads

381

Posts

5

Reputation

Show all posts

original poster lrh2006 posted 2015-5-22 13:56
谢谢各位

Quick Reply

Advanced Mode
B Color Image Link Quote Code Smilies
You have to log in before you can reply Login | Register account

$\LaTeX$ formula tutorial

Mobile version

2025-7-15 14:06 GMT+8

Powered by Discuz!

Processed in 0.014329 seconds, 25 queries