if m=sinA/sinB ,n=tanA/tanB then cos2A=M2-1/N2-1

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if m=sinA/sinB ,n=tanA/tanB then cos2A=M2-1/N2-1

Lalit Mehra · Accepted Answer

Hi! Here is the answer to your question

⇒m2 – n2 cos2A = sin2A ⇒m2 – n2 cos2A = 1 – cos2A ⇒n2cos2A – cos2A = m2 – 1 ⇒ (n2 – 1) cos2A = m2 – 1

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