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Grade 12th PassAnalytical Geometry

If P≡(1/xp,p);Q≡(1/xq,q);R≡(1/xr,r) where xk≠0,k=p,q,r belong to N,denotes the kth term of a harmonic progression,then

a.Area(ΔPQR)={(p2q2r2)/2}√((p-q)2+(q-r)2+(r-p)2)

b.ΔPQR is a right angled triangle

c.the points P,Q and R are collinear

d.none of these

Profile image of Menka Malguri
14 Years agoGrade 12th Pass
Answers icon

1 Answer

Profile image of Mera Andaaz
6 Years ago
1/xp = a + ( p – 1)d
1/xq = a + ( q – 1)d
1/xr  = a + ( r – 1)d
 
Determinant  =  0
 |a + ( p – 1)d    p    1|
 |a + ( q – 1)d    q    1|     =    0
 |a + ( r – 1)d     r     1|
 
Therfore Answer is (c)

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