Simplify trigonometric expression

courteous

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Simplify: 2sinx+132cosx\displaystyle \frac{2\sin{x}+1}{\sqrt3 - 2\cos{x}}

What I've come to thus far (by multiplying with 3+2cosx3+2cosx\displaystyle \frac{\sqrt3 + 2\cos{x}}{\sqrt3 + 2\cos{x}} and 2sinx12sinx1\displaystyle \frac{2\sin{x}-1}{2\sin{x}-1}) is 3+2cosx2sinx1\displaystyle \frac{\sqrt3 + 2\cos{x}}{2\sin{x}-1} :x

Oh, not to forget, the solution deals with cot\displaystyle \cot (cotangens).
 
courteous said:
Simplify: 2sinx+132cosx\displaystyle \frac{2\sin{x}+1}{\sqrt3 - 2\cos{x}}

What I've come to thus far (by multiplying with 3+2cosx3+2cosx\displaystyle \frac{\sqrt3 + 2\cos{x}}{\sqrt3 + 2\cos{x}} and 2sinx12sinx1\displaystyle \frac{2\sin{x}-1}{2\sin{x}-1}) is 3+2cosx2sinx1\displaystyle \frac{\sqrt3 + 2\cos{x}}{2\sin{x}-1} :x

Oh, not to forget, the solution deals with cot\displaystyle \cot (cotangens).

Please share with us the "exact" form you are given as answer.

Without knowing the form that is wanted - I would do it the following way

2sin(x)+132cos(x)\displaystyle \frac{2sin(x) + 1}{\sqrt{3}-2cos(x)}

=sin(x)+1232cos(x)\displaystyle = \, \frac{sin(x) + \frac{1}{2}}{\frac{\sqrt{3}}{2}-cos(x)}

=sin(x)+sin(π6)cos(π6)cos(x)\displaystyle = \, \frac{sin(x) + \, sin(\frac{\pi}{6})}{cos(\frac{\pi}{6}) \, - \, cos(x)}

then use the fact that:

sin(A)+sin(B)=2sin(A+B2)cos(AB2)\displaystyle sin(A) \, + \, sin(B) \, = \, 2\cdot sin(\frac{A+B}{2})\cdot cos(\frac{A-B}{2})

and similar form for cosines.

That should take you to the "allegedly simlified" cotangent form.
 
With sum as product, I managed to take it to given solution cotxπ62\displaystyle \cot\frac{x-\frac{\pi}{6}}{2}.
 
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