What is the value of 9 cot2θ 9 cosec2θ?

To find: 9 cot2 θ – 9 cosec2 θ

Consider 9 cot2 θ – 9 cosec2 θ = 9 (cot2 θ – cosec2 θ)


Now 1 + cot2 θ = cosec2 θ


cot2 θ – cosec2 θ = – 1


9 cot2 θ – 9 cosec2 θ = 9 (cot2 θ – cosec2 θ) = 9 ( – 1) = – 9


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