Try double angle formula
I guess Trigonometry question go in the Trigonometry section. That makes sense.
I was having trouble with this question (See attachment) as I'm not sure how to change it into a sum or something similar to find the general solution. I’m not sure if I need to use identities or a product to sum formula or something similar. If someone could work me through it, it would be greatly appreciated.
songoku,
I'm not sure how to use the double angle formula a second time and then factorise it. It would be helpful if you could show me how to do that and then showhow to factorise it.
Thanks.
wow, really nice work mr_fantastic
btw, I mean like this :
2sin2xcos2x-cosx = 0
4 sin x cos x cos 2x - cos x = 0
(cos x) (4 sin x cos 2x - 1 ) = 0
cos x = 0 or 4 sin x cos 2x - 1 = 0
Use the double angle formula again on cos 2x and state the equation in term of sin x
but mr_fantastic has given a really elegant way