Solve equation sin(x + 15 ) = 3cos(x - 15) for 0 - 360 degrees.
I started with
sinx cos15 + cosx sin15 = 3( cosx cos15 + sinx sin15)
i don't know where to go now
thanks
g
Put all the terms with $\displaystyle \sin x$ on one side and all the terms with $\displaystyle \cos x$ on the other. Then factor out $\displaystyle \sin x$ and $\displaystyle \cos x$ from their respective sides, so you get something like:
$\displaystyle \sin x(\cos 15 - 3\sin 15) = \cos x(3 \cos 15-\sin 15)$
Now assuming $\displaystyle x \ne 90^o$ and $\displaystyle x \ne 270^o$, divide everything by $\displaystyle \cos x$, and you'll need to remember a very well known trig identity here to complete the final step.