well now i got my mistake...
i took t1.t2=-1... dats y...
two mutually perpendicular chords OA and OB are drawn through the vertex O of a parabola y2=4ax. Then the locus of the circumcenter of the triangle OAB...
i got the ans y2=2ax-2a2
is it wrong??? plz reply
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5 Answers
give me a few mins.. u will get the ans..
but to know what is wrong.. i need to know how u reached there!
seems a straightforward question...
two points be (at12, 2at1) and (at22, 2at2)
let the slope of the first from the origin(vertex) be m, -1/m (bcos perpendicular)
hence, 2at1/at12 = m
2/t1 = m
and
2at2/at22 = -1/m
2/t2 = -1/m
now it should be straighforward...
If u have reached uptil here, then there is some calculation mistake.. but i will finish this question in the next post
So, we have
t1t2 = - 4
midpoint is given by
{a(t12+t22)/2, a(t1+t2)}
let h,k be the locus...
h=a(t12+t22)/2
k=a(t1+t2)}
2h/a = t12+t22
(k/a)2 = (t1+t2)2
= t12+t22 + 2 t1t2
(k/a)2 = 2h/a -8
Forgive my calculation or step mistakes if any :)