21
eragon24 _Retired
·2009-11-27 12:03:12
see its easy
let vertex A be origin(0,0)
vertex B be (k,0)
vertex C be(p,q)
now eq of circle with AB as diameter is
(x-k2)2 + y2=k2/4......................i
now centriod of triangle is (p+k3 ,q3)
since circle passe through it we get
(p+k3-k2)2 +(q3)2 =k2/4 ................ii
now since we know AC is 4 and BC is 3
so we get p2+q2=16...........................ii
(p-k)2 +q2=9......................................iii
now we hav 3 eq and 3 variables
eliminating p and q we get k =√5.....so length of side AB IS √5
19
Debotosh..
·2009-11-27 21:05:36
no need to take such calculations
....use apollonius theorem ! its done!
1
Kaustab Sarkar
·2009-11-27 21:56:37
how wud u use appolonius theorem here....i tried but cudnt get debtosh....cud u plz show
21
eragon24 _Retired
·2009-11-27 22:33:41
@debo i din thought of appolonius theorem though....perhaps in the soln booklet they must hav given soln with tat only....but how does it matter...i did it in another way....though slight lengthy[1][3]
4
UTTARA
·2009-11-28 04:40:03
Thanks eragon24 , debotosh & swathi
19
Debotosh..
·2009-11-28 09:59:23
we must not go for lengthy , customary methods in these exams....it takes away a lot of time,,,,just thinking for 1 minute can give you a very brief method ,,,just as i i got while doing this sum !