1.

The locus of a point whose chord of contact with respect to the circle `x^2+y^2=4`is a tangent to the hyperbola `x y=1`is a/anellipse(b) circlehyperbola (d) parabolaA. ellipseB. circleC. hyperbolaD. parabola

Answer» Correct Answer - C
Let the point be (h, k).
Then the equation of the chord of contact is `hx+ky=4.`
Since `hx+ky=4` is tangent to xy = 1,
`x((4-hx)/(k))=1`
has two equal roots.
Therefore, discriminant of `hx^(2)-4x+k=0` is 0.
`therefore" "hk=4`
Thus, the locus of (h, k) is xy = 4.


Discussion

No Comment Found

Related InterviewSolutions