If (a,1/a), (b,1/b),(c,1/c),(d,1/d) are four distinct points on a circle of radius 4 units then,abcd is equal to??
Ans) As they are of form (x,1/x)
let eq of circle be x2+y2+2gx+2fy+c=0
it passes by general pt (x,1/x)
Substituting we get 4th degree in x
a,b,c,d are roots of it
by theory of equations it is constant term/coefficient of x2
then it comes to be 1