 # Q1 If PN is the perpendicular from a point on a rectangular hyperbola to its asymptotes, the locus, the midpoint of PN is a/an Q2  The product of perpendiculars from any point on the  hyperbola   having general equation  to is asymptotes is equal to?2 If PN is the perpendicular from a point on a rectangular hyperbola to its asymptotes, the locus, the midpoint of PN is a/an Badiuddin askIITians.ismu Expert
148 Points
12 years ago

Dear Zahid

let equation of hyperbola is   x2 -y2 =a2

and equation os aymptote is  :   y=x   (slope  m=1)

let N(x1,x1) on the asymptote ,and a point P(asecθ ,atanθ) on the hyperbola and(h,k) is the mid point of PN

h=(x1+asecθ)/2   or  asecθ =2h-x1 ...............1

k = (x1+atanθ)/2  or  atanθ =2k-x1 ................2

since PN is perpendiculat to aymptote so slope of PN =-1

(k-x1)/(h-x1)=-1

x1 =(h+k)/2

so put this value in equation 1 and 2

asecθ=(3h-k)/2

atanθ =(3k-h)/2

now square and subtract

a2(sec2θ -tan2θ) = {(3h-k)/2}2 - {(3k-h)/2}2

a2 = {(3h-k)/2}2 - {(3k-h)/2}2

4a2 =8(h2-k2)

h2-k2=a2/2

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