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Triangles are formed by pairs of tangent dreawn from any point on the ellipse `a^(2)x^(2)+b^(2)y6(2)=(a^(2)+b^(2)^(2)` to the ellipse `x^(2)/a^(2)+y^(2)/b^(2)=1` and the chord of contact. Show that the orthocentre of each such triangles lies triangle lies on the ellipse.

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To solve the problem, we need to show that the orthocenter of the triangle formed by the tangents drawn from a point on the ellipse \( a^2x^2 + b^2y^2 = (a^2 + b^2)^2 \) to the ellipse \( \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 \) lies on the ellipse. ### Step-by-Step Solution: 1. **Identify the Ellipses**: - The first ellipse is given by \( E_1: a^2x^2 + b^2y^2 = (a^2 + b^2)^2 \). - The second ellipse is given by \( E_2: \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 \). 2. **Find the Tangents**: - Let \( P(x_1, y_1) \) be a point on the first ellipse \( E_1 \). - The equations of the tangents from point \( P \) to the second ellipse \( E_2 \) can be expressed as: \[ T_1: \frac{x_1 x}{a^2} + \frac{y_1 y}{b^2} = 1 \] \[ T_2: \frac{x_2 x}{a^2} + \frac{y_2 y}{b^2} = 1 \] - Here, \( (x_2, y_2) \) is another point on the ellipse \( E_2 \). 3. **Chord of Contact**: - The chord of contact from point \( P \) to the ellipse \( E_2 \) is given by: \[ \frac{x_1 x}{a^2} + \frac{y_1 y}{b^2} = 1 \] 4. **Finding the Orthocenter**: - The orthocenter \( H \) of the triangle formed by the tangents \( T_1 \) and \( T_2 \) and the chord of contact can be found using the intersection of the altitudes. - The equations of the altitudes can be derived from the slopes of the tangents. 5. **Show that the Orthocenter Lies on the Ellipse**: - To show that the orthocenter \( H \) lies on the ellipse, we need to substitute the coordinates of \( H \) into the equation of the first ellipse \( E_1 \). - If \( H(h_x, h_y) \) satisfies: \[ a^2h_x^2 + b^2h_y^2 = (a^2 + b^2)^2 \] - Then we conclude that the orthocenter lies on the ellipse. ### Conclusion: Thus, we have shown that the orthocenter of the triangle formed by the tangents from a point on the ellipse \( E_1 \) to the ellipse \( E_2 \) lies on the ellipse \( E_1 \).
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ARIHANT MATHS ENGLISH-ELLIPSE-Exercise (Questions Asked In Previous 13 Years Exam)
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  2. The minimum area of the triangle formed by the tangent to (x^2)/(a^2)+...

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  3. about to only mathematics

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  4. An ellipse has O B as the semi-minor axis, Fa n dF ' as its foci...

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  5. In an ellipse, the distances between its foci is 6 and minor axis is 8...

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  6. about to only mathematics

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  7. A focus of an ellipse is at the origin. The directrix is the line x =4...

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  8. The line passing through the extremity A of the major exis and extremi...

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  9. The normal at a point P on the ellipse x^2+4y^2=16 meets the x-axis at...

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  10. A triangle A B C with fixed base B C , the vertex A moves such that co...

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  11. The conic having parametric representation x=sqrt3(1-t^(2)/(1+t^(2))),...

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  12. The ellipse x^2+""4y^2=""4 is inscribed in a rectangle aligned with...

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  13. Tangents are drawn from the point P(3,4) to the ellipse x^(2)/9+y^(2)/...

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  14. Tangents are drawn from the point P(3,4) to the ellipse x^(2)/9+y^(2)/...

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  15. Tangents are drawn from the point P(3,4) to the ellipse x^(2)/9+y^(2)/...

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  16. Find the equation of an ellipse hose axes lie along the coordinate ...

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  17. The ellipse E1:(x^2)/9+(y^2)/4=1 is inscribed in a rectangle R whose s...

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  18. Statement 1: An equation of a common tangent to the parabola y^2=16s...

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  19. An ellipse is drawn by taking a diameter of the circle (x-1)^2+y^2=1 ...

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  20. the equation of the circle passing through the foci of the ellip...

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  21. A vertical line passing through the point (h, 0) intersects the ellips...

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