Ask your own question, for FREE!
Mathematics 20 Online
OpenStudy (anonymous):

How do i prove the addition formula for cosine? Cos(u+v) = cos u cos v - sin u sin v

OpenStudy (anonymous):

look in the book, i am sure it is proved there. if you know fancier math (say euler's formula) then this is a direct result of the laws of exponents. if not you have to use a geometric argument, and it is rather cumbersome although completely doable

OpenStudy (anonymous):

Unfortunately it doesn't prove it there. Do u know anywhere on a website where it proves it ?

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!