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The tangent to x^(2)//a^(2)+y^(2)//b^(2)...

The tangent to `x^(2)//a^(2)+y^(2)//b^(2)=1` meets the major and minor axes in P and Q respectively, then `a^(2)//CP^(2)+b^(2)//CQ^(2)=`

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To solve the problem, we need to find the value of \( \frac{a^2}{CP^2} + \frac{b^2}{CQ^2} \) where \( CP \) and \( CQ \) are the distances from the center of the ellipse to the points where the tangent meets the major and minor axes. ### Step-by-Step Solution: 1. **Equation of the Ellipse**: The equation of the ellipse is given as: \[ \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 \] 2. **Tangent to the Ellipse**: The equation of the tangent to the ellipse at an angle \( \theta \) can be expressed as: \[ \frac{x \cos \theta}{a} + \frac{y \sin \theta}{b} = 1 \] 3. **Finding Points P and Q**: - **Point P (on the major axis)**: Set \( y = 0 \) in the tangent equation to find \( x \): \[ \frac{x \cos \theta}{a} = 1 \implies x = \frac{a}{\cos \theta} \] Thus, the coordinates of point P are \( \left(\frac{a}{\cos \theta}, 0\right) \). - **Point Q (on the minor axis)**: Set \( x = 0 \) in the tangent equation to find \( y \): \[ \frac{y \sin \theta}{b} = 1 \implies y = \frac{b}{\sin \theta} \] Thus, the coordinates of point Q are \( \left(0, \frac{b}{\sin \theta}\right) \). 4. **Calculating Distances CP and CQ**: - The distance \( CP \) from the center to point P is: \[ CP = \frac{a}{\cos \theta} \] - The distance \( CQ \) from the center to point Q is: \[ CQ = \frac{b}{\sin \theta} \] 5. **Calculating \( CP^2 \) and \( CQ^2 \)**: - \( CP^2 = \left(\frac{a}{\cos \theta}\right)^2 = \frac{a^2}{\cos^2 \theta} \) - \( CQ^2 = \left(\frac{b}{\sin \theta}\right)^2 = \frac{b^2}{\sin^2 \theta} \) 6. **Finding \( \frac{a^2}{CP^2} + \frac{b^2}{CQ^2} \)**: - Substitute the values of \( CP^2 \) and \( CQ^2 \): \[ \frac{a^2}{CP^2} = \frac{a^2}{\frac{a^2}{\cos^2 \theta}} = \cos^2 \theta \] \[ \frac{b^2}{CQ^2} = \frac{b^2}{\frac{b^2}{\sin^2 \theta}} = \sin^2 \theta \] - Therefore, we have: \[ \frac{a^2}{CP^2} + \frac{b^2}{CQ^2} = \cos^2 \theta + \sin^2 \theta \] 7. **Using the Pythagorean Identity**: - We know that: \[ \cos^2 \theta + \sin^2 \theta = 1 \] 8. **Final Result**: Thus, the final answer is: \[ \frac{a^2}{CP^2} + \frac{b^2}{CQ^2} = 1 \]
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