Question 339978
Since both {{{cos(pi/3)=1/2}}} and {{{cos(-pi/3)=1/2}}}, this means that *[Tex \LARGE \cos^{-1}(\frac{1}{2})=\frac{\pi}{3}] or *[Tex \LARGE \cos^{-1}(\frac{1}{2})=-\frac{\pi}{3}]. You can add {{{2pi}}} to the second angle to get {{{-pi/3+2pi=5pi/3}}}



So *[Tex \LARGE \cos^{-1}(\frac{1}{2})=\frac{\pi}{3}] or *[Tex \LARGE \cos^{-1}(\frac{1}{2})=\frac{5\pi}{3}] where the angle is in the interval from 0 to {{{2pi}}}



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