# Odd Geometric progression

Geometry Level 4

A geometric progression $$a_n$$ satisfies:

$a_1 = \sin x, \ a_2 = \cos x, \ a_3 = \tan x, \ \ldots$

for a certain value of $$x$$.

For what value of $$n$$ do we have $$a_n = 1 + \cos x$$?

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