Trigonometry

Find the solution {in the interval of [0,2pi)} of: tan2x - 2cosx = 0 ( I know the answer is pi/6, but I guessed and checked. Please show the steps I need to go through in order to get the answer )

What are these things called: -cos x = cos -x What are the rules to these trig rules? Thanks

Thanks for the prompt reply. How do these work out? The Odd/Even Identities? sin -x = -sin x cos -x = cox x tan -x = -tanx Why does this work out? Does it apply to certain quadrants or something? Thanks.

Mr. Abad is beside a Santol tree S which is directly west of a Mango tree M. He walks straight to the point A 63.6 meters North, and finds that angle SMA is 51 degrees 36 minutes.

Mr. Abad is beside a Santol tree S which is directly west of a Mango tree M. He walks straight to the point A 63.6 meters North, and finds that angle SMA is 51 degrees 36 minutes. a) What is the distance between the two trees? b) How far is he from the Ma...

The Sibago Island lighthouse in Zamboanga stands on a rock 163.4 meters above sea level. A man in a vinta 151.6 meters away from the vertical axis of the light house, observes that the angle of elevation of the top of the lighthouse is 51 degrees 7 minute...