which are true for all positive integral values for n=1 x+(1/x)=2cos theta

Question

Which ar true for all positive integral values for n>=1 interms of cos and interms of sign.

Victoria V. · Accepted Answer

What are my choices?  It asks "which are true", yet I see no choices.  I am thinking this question is incomplete.  Can you send more?

which are true for all positive integral values for n>=1 x+(1/x)=2cos theta