Question

tan9°+tan36°+tan9°tan36°=1

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Answer 1

Answer:

We know that, tan45 = 1 ⇒ tan (36 + 9) = 1 ⇒ (tan36 + tan9)/(1 - tan36 tan9) = 1, using the identity tan(A + B) = (tanA + tanB)/(1)