easy question Watch

This discussion is closed.
hamidreza.com
Badges:
#1
Report 15 years ago
#1
Hi everybody
i have an easy question that i cannot solve it?
if x+y=4
then what is the min of (1/x+1/y)
??????????????
Unregistered
Badges:
#2
Report 15 years ago
#2
Hi,
If X+Y=4, then X can be any of 0, 1, 2, 3 or 4, while at the same time, Y can be any of 4, 3, 2, 1 or 0; so that the sum X+Y is equal to 4.

0 is Invalid number, as any fraction with Zero as denominator is invalid or infinity. This makes 4 also an invalid choice.

From the other combination the least value for 1/X + 1/Y is obtained only with X & Y = 2.

Hence least value of 1/X + 1/Y = 1

Bala
X
new posts
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Do you like exams?

Yes (186)
18.98%
No (590)
60.2%
Not really bothered about them (204)
20.82%

Watched Threads

View All
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise