Question

tan x + 2 tan 2x + 4 tan 4x + 8 cot8x​

Answer 1

Answer:

e^iθ ≡cos θ+ isin θ

This is an IDENTITY, meaning for whatever value of θ. LHS =RHS.

Using θ=½π,

LHS=e^(i(½π))

RHS=cos(½π)+isin(½π)

=0+i(1)

=i