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Question
If x = a cos θ and y = b cot θ, show that:
`a^2/x^2 - b^2/y^2 = 1`
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Solution
`a^2/x^2 - b^2/y^2`
= `a^2/(a^2cos^2theta) - b^2/(b^2cot^2theta)`
= `1/cos^2theta - sin^2theta/cos^2theta`
= `(1 - sin^2theta)/cos^2theta`
= `cos^2theta/cos^2theta`
= 1
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