równanie trygonometryczne

[jezik]

\(\displaystyle{ 2\cos \frac{2}{x} = \cos \frac {\pi}{6}}\)

[Lorek]

\(\displaystyle{ \cos \frac{2}{x}=\frac{\sqrt{3}}{4}\\\frac{2}{x}=\pm \arccos \frac{\sqrt{3}}{4}+2k\pi\\x=\frac{2}{\pm \arccos \frac{\sqrt{3}}{4}+2k\pi}}\)