TrigIdentity BasicSequence AMC10/12 Intermediate

2010

Problem - 688

A geometric sequence $(a_n)$ has $a_1=\sin x$, $a_2=\cos x$, and $a_3= \tan x$ for some real number $x$. For what value of $n$ does $a_n=1+\cos x$?

The solution for this problem is available for $0.99.
You can also purchase a pass for all available solutions for $99.