Question

Show that 1 ➖ tan square A by cot square A ➖ 1 is equals to tan square A

Answer 1

Solution:

LHS = (1-tan²A)/(cot²A-1)

=(1-tan²A)/[(1/tan²A)-1]

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Since, cotA = 1/tanA

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= (1-tan²A)/[(1-tan²A)/tan²A]

After cancellation, we get

= tan²A

= RHS

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