Math Is Fun Forum

saudi_boy

Member

Registered: 2006-11-01

Posts: 41

Max and Min Problem

Hey everybody,,,

can u help me with this question??

Find three positive numbers whose sum is 27 and such that the
sum of their squares is as small as possible.??

I think we need to use Partial Derivatives..

I really need the solution..

thanks..

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Max and Min Problem

We can let the three numbers be

,

,

, where

.

Sum of squares

Hence S is minimized if and only if

is minmized, i.e. if and only if

.

So the three numbers are 9, 9, 9.

I solved the problem without calculus, woohoo.

saudi_boy

Member

Registered: 2006-11-01

Posts: 41

Re: Max and Min Problem

wooooooow

good job,, JaneFairfax

,, thank you very much

your solution is perfectly true
,,

thanks again

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Max and Min Problem

I am bumping this thread to remind everyone how smart I was (and still am).

iamfriendly

Member

Registered: 2009-07-03

Posts: 72

Re: Max and Min Problem

that's probably why you're legendary

---

EYE AM FRIENDLY, THAT'S O U NEED 2 NO,
psst,
Don't trust strangers, EYE AM FRIENDLY, THAT'S O U NEED 2 NO ..........psst, Don't trust strangers......

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Max and Min Problem

I am bumping this thread to remind everyone how smart I was (and still am).

I never forgot. Can I assume that this is your favorite post? The one that showcases you best?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.