62
Lokesh Verma
·2009-03-13 03:31:15
Hint Use the trick that was used to prove that among all quadrilaterals, square has maximum area!
39
Dr.House
·2009-03-13 03:33:52
gemoetry? not in jee syllabus. people say so
62
Lokesh Verma
·2009-03-13 03:36:02
Nothing to know about geometry here... or should i say hardly anything
whatever is needed is in the Trigonometry syllabus!
39
Dr.House
·2009-03-13 03:41:38
If we then go to an n-sided figure with perimeter P, the area of one
of the triangle formed by joining the midpoint of the figure
to the vertices is:
(1/2)r x cos(pi/n) x P/n
where r = distance from centre point to a vertex),
and with n such
triangles the area is (1/2)r x P x cos(pi/n).
This will tend to its greatest value as cos(pi/n) -> 1 which requires
that n -> infinity.
So we in the end get a polygon of an infinite number
of sides, which is a circle.
62
Lokesh Verma
·2009-03-13 04:06:28
have you used regular polygon ?
39
Dr.House
·2009-03-13 04:08:15
ok, we have a theorem which states of all polygons, regular polygon has maximum area.
11
Mani Pal Singh
·2009-03-13 04:19:52
shayad sir aapne isse dekha nahin
but bharghav has given this link in chatbox
http://www.mathlinks.ro/viewtopic.php?t=264064
62
Lokesh Verma
·2009-03-13 04:23:08
What am i supposed to do with this?
@b555.. You have proved only that among regular polygons, circle has highest area..
You have proved nothing for "All Polygons"
11
Mani Pal Singh
·2009-03-13 04:24:11
mujhe laga woh uss ne aap ke liye diya tha [2]
39
Dr.House
·2009-03-13 04:27:00
sirry that link was only inspirit of a good problem, nothing to do with question here
ok i am trying for all polygons
39
Dr.House
·2009-03-13 04:29:01
WHAT I DID WAS MAY BE A BIT LONG BUUT CORRECT METHOD.
AMONG ALL POLYGONS , REGULAR POLYGONS HAVE HIGHEST AREA AND AMONG ALL REGULAR POLYGONS CIRCLE HAS MAXIMUM AREA, HENCE
AMONG ALL POLYGONS, CIRCLE HAS MAXIMUM AREA.
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Lokesh Verma
·2009-03-13 04:30:11
The second part essentially has the same proof bhargav!
9
Celestine preetham
·2009-03-13 04:58:25
take a loop of given lenght and extend it outwards to get max area itll be a circle
62
Lokesh Verma
·2009-03-13 05:00:48
Yes there is one person who reads the question of the days ;)