Can this be solved w/o graphing?
sin 3x = cos x

Question

anonymous · Answer

I think you will need to use triple angle identities

anonymous · Answer

you use the double angle formula or half angle formula

myininaya · Answer

i dont know if it possible to find exact solutions

anonymous · Answer

it is because because you haave to play around with it to  find the correct answer it sums up to equal the other side

myininaya · Answer

oh i got it

myininaya · Answer

we have sin3x=sin(pi/2-x)
3x=pi/2-x
4x=pi/2
x=pi/8

anonymous · Answer

just keep trying

myininaya · Answer

i dont have to i got it lol

anonymous · Answer

well congratz

myininaya · Answer

we call also make a answer general by saying x=pi/8+2npi for n=..-2,-1,0,1,2,...

anonymous · Answer

yu can say that but stil make sure that is definately the right answer its alwayz good to double check

myininaya · Answer

and 
we also have x=5pi/8+2npi for n=..-2,-1,0,1,2,..

nikvist · Answer

$$x=\frac{\pi}{4}+\pi k\quad\vee\quad x=\frac{\pi}{8}+\frac{\pi}{2}k\quad,\quad k\in\mathbb{Z}$$