Trigonometry
Solve the following equation for x if x lies in the interval [0,π]\left[0,\pi\right\rbrack[0,π].
y=13cosxy=13\cos xy=13cosx
x=cos−1(y13)x=\cos^{-1}\left(\frac{y}{13}\right)x=cos−1(13y)
x=113cos−1yx=\frac{1}{13}\cos^{-1}yx=131cos−1y
x=cos−1(13y)x=\cos^{-1}\left(13y\right)x=cos−1(13y)
x=12cos−1yx=12\cos^{-1}yx=12cos−1y