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Question
What is the value of 9cot2 θ − 9cosec2 θ?
Solution
We have,
`9 cot^2 θ-9 cosec^2θ= 9(cot ^2θ-cosec^2 θ) `
=` -9(cosec ^2θ-cot θ)`
We know that, `cosec ^2 θ-cot ^2 θ-1`
Therefore,
\[9 \cot^2 \theta - 9 {cosec}^2 \theta = - 9\]
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