sin x - sqrt3 cos x=1
write as a single function of sine
thank you but that is where I am getting confused. lol
\[a\sin(x)+b\cos(x)=\sqrt{a^2+b^2}\sin(x+\theta)\] where \[\sin(\theta)=\frac{b}{\sqrt{a^2+b^2}}\] and \[\cos(\theta)=\frac{a}{\sqrt{a^2+b^2}}\]
sometimes you can use \[\theta=\tan^{-1}(\frac{b}{a})\] but not always
you good from there? this one is cooked up to be more or less easy
not really these problems I tend to make ten times harder than it needs to be.
in your case \(a=1,b=\sqrt3\) so \(\sqrt{a^2+b^2}=\sqrt{1+3}=\sqrt4=2\)
actually \(b=-\sqrt3\) but it makes no difference when you square it
as for \(\theta\), you have to find a number (angle if you prefer) where \[\sin(\theta)=\frac{b}{a}=-\frac{\sqrt3}{2}\] and \[\cos(\theta)=\frac{1}{2}\] this should look familiar
oops i did not mean \(\sin(\theta)=\frac{b}{a}\) i meant \(\sin(\theta)=\frac{ b}{\sqrt{a^2+b^2}}\)
so if the answer needs to be on an interval from 0 to 2pi i would add the period to the answer until i reach 2pi?
we are not close to done yet what is \(\theta\)?
oh lol they dont have give what theta is
the instruction say give the answer in exact form on the interval of [0, 2pi) the question itself is sin theta - square root 3 cos theta = 1
you can square both sides to get \(sin^2 -2\sqrt{3} sin~ cos +3 cos^2 =1\) and separate to \(sin^2 + cos^2 +2 cos^2 -2 \sqrt{3}sin~ cos=1\), you have \(sin^2 + cos^2 =1\) cancel out with the right handside, therefore, just \(2cos^2 -2\sqrt{3}sin~cos=0\) factor 2cos out, \(2cos (cos -\sqrt{3}sin) =0\) so, cos =0 or \(cos -\sqrt{3}sin =0\) in that interval, cos =0 iff \(\theta =\dfrac{\pi}{2}~ or ~\theta=\dfrac{3\pi}{2}\) \(cos - \sqrt{3}sin =0\\cos = \sqrt{3}sin\\\dfrac{cos}{sin}= \sqrt{3}\\cot =\sqrt{3}\) you do the leftover
thank you very much for your help
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