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The chords of contact of a point with respect to a hyperbola and its auxillary circle are perpendicular, then the point lies on :

A

One of the directrices

B

one of the asymptotes

C

conjugate hyperbola

D

Axis of hyperbola

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To solve the problem, we need to find the locus of a point \( P(h, k) \) such that the chords of contact with respect to a hyperbola and its auxiliary circle are perpendicular. ### Step-by-Step Solution: 1. **Equation of the Hyperbola**: The standard equation of the hyperbola is given by: \[ \frac{x^2}{a^2} - \frac{y^2}{b^2} = 1 \] 2. **Equation of the Auxiliary Circle**: The auxiliary circle of the hyperbola has the equation: \[ x^2 + y^2 = a^2 \] 3. **Chords of Contact**: The equation of the chord of contact from the point \( P(h, k) \) to the hyperbola is given by: \[ \frac{hx}{a^2} - \frac{ky}{b^2} = 1 \] The equation of the chord of contact from the point \( P(h, k) \) to the auxiliary circle is: \[ hx + ky = a^2 \] 4. **Finding Slopes**: - For the hyperbola, rearranging the chord of contact gives: \[ ky = hx - a^2 \implies y = \frac{h}{k}x - \frac{a^2}{k} \] The slope \( m_1 \) of this line is: \[ m_1 = \frac{h}{k} \] - For the auxiliary circle, rearranging gives: \[ ky = a^2 - hx \implies y = -\frac{h}{k}x + \frac{a^2}{k} \] The slope \( m_2 \) of this line is: \[ m_2 = -\frac{h}{k} \] 5. **Condition for Perpendicularity**: The chords are perpendicular if the product of their slopes is -1: \[ m_1 \cdot m_2 = -1 \] Substituting the slopes: \[ \left(\frac{h}{k}\right) \left(-\frac{h}{k}\right) = -1 \] This simplifies to: \[ -\frac{h^2}{k^2} = -1 \implies h^2 = k^2 \] 6. **Locus of the Point**: From \( h^2 = k^2 \), we can write: \[ \frac{h^2}{a^2} - \frac{k^2}{b^2} = 0 \] Replacing \( h \) with \( x \) and \( k \) with \( y \), we get: \[ \frac{x^2}{a^2} - \frac{y^2}{b^2} = 0 \] This represents the asymptotes of the hyperbola, which can be factored as: \[ \left(\frac{x}{a} - \frac{y}{b}\right)\left(\frac{x}{a} + \frac{y}{b}\right) = 0 \] ### Conclusion: Thus, the locus of the point \( P(h, k) \) lies on the asymptotes of the hyperbola.

To solve the problem, we need to find the locus of a point \( P(h, k) \) such that the chords of contact with respect to a hyperbola and its auxiliary circle are perpendicular. ### Step-by-Step Solution: 1. **Equation of the Hyperbola**: The standard equation of the hyperbola is given by: \[ \frac{x^2}{a^2} - \frac{y^2}{b^2} = 1 ...
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