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If the chords of contact of tangents from twopoinst `(x_1, y_1)`and `(x_2, y_2)`to theellipse `(x^2)/(a^2)+(y^2)/(b^2)=1`are atright angles, then find the value of `(x_1x_2)/(y_1y_2)dot` |
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Answer» Correct Answer - `-a^(4)//b^(4)` The equations of the chords of contact of tangents drawn from `(x_(1),y_(1)) and (x_(2),y_(2))` to the ellipse `(x^(2))/(b^(2))+(y^(2))/(b^(2))=1` are `(x x_(1))/(a^(2))+(yy_(1))/(b^(2))=1" "(1)` `(x x_(2))/(a^(2))+(yy_(2))/(b^(2))=1" "(2)` It is given that (1) and (2) are at right angles. Therefore, `(-b^(2))/(a^(2))(x_(1))/(y_(1))xx(-b^(2))/(a^(2))(y_(2))/(y_(2))=-1` or `(x_(1)y_(1))/(y_(1)y_(2))=-(a^(2))/(b^(4))` |
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