Question

Prove it:
cotx - tanx - 2tan2x - 4tan4x = 8cot8x​

Answer 1

Answer:

we have to prove that

cotx -tanx -2tan2x - 4tan4x = 8cot8x

or,

thanx + 2tan2x + 4tan4x +8cot8x = cotx

formula used in the above proof:

tan2x = 2tanx/(1 - tan²x)

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