Find the sum of cos 1⁰ + cos 2⁰ + cos 23⁰ +…..+ cos 179⁰.
I know the sum would be zero but I can't show how to get it. Please help me to arrive an algebraic.
Take pairs from opposite ends such that
edit: Removed working because as Archie Meade pointed out in post 3 the difference is not 180. The sum is still 180 though and because each sum is 180 the answer is 0 since we're multiplying by 0.
Perhaps it would be better to follow the working in post 3 for a more complete solution