Show that cos(π/7)  cos(2π/7) + cos(3π/7) = 1/2.
Perhaps someone will be so kind as to explain this one to me. I am thinking that n can be any number, so I arbitrarily choose 35 and observe hierarchy and do not get that cos5cos10+cos15 = 1/2.
I'm not familiar with the principle involved but if such a thing does exist then wouldn't it be a modulus behaviour based on the cyclic properties of sine and cosine functions?
Thank you. Hugs. CeeAnne

Posted by CeeAnne
on 20041206 21:20:43 