$A=\sqrt{x-3}+\sqrt{5-x}$
Edited by perfectstrong, 05-12-2011 - 22:28.
#1
Posted 05-12-2011 - 18:26
snowangel1103
-
- Thành viên
-
- 77 posts
Hạ sĩ
tìm x để A đạt giá trị lớn nhất
$A=\sqrt{x-3}+\sqrt{5-x}$
$A=\sqrt{x-3}+\sqrt{5-x}$
#2
Posted 05-12-2011 - 18:30
Ispectorgadget
-
- Quản lý Toán Phổ thông
-
- 2946 posts
Nothing
A$\leq \sqrt{(1+1)(x-3+5-x)}=\sqrt{2.2}=2$
Dấu "=" xảy ra khi x=4
Dấu "=" xảy ra khi x=4
- perfectstrong and snowangel1103 like this
►|| The aim of life is self-development. To realize one's nature perfectly - that is what each of us is here for. ™ ♫
#3
Posted 07-12-2011 - 18:10
snowangel1103
-
- Thành viên
-
- 77 posts
Hạ sĩ
$A= \sqrt{x-3}+\sqrt{5-x} = \sqrt{x-3}.1+\sqrt{5-x}.1 \leq \frac{x-3+1}{2}+\frac{5-x+1}{2}=2$
dấu "=" xảy ra khi x=4
vậy A max =2 khi x=4
dấu "=" xảy ra khi x=4
vậy A max =2 khi x=4
Edited by perfectstrong, 07-12-2011 - 21:39.
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users
