Solve {l}{cos(a)=1/4}{b=a}{c=b}{text{Solvefor}dtext{where}}{d=c}

$$\left. \begin{array} { l } { \cos(a) = \frac{1}{4} }\\ { b = a }\\ { c = b }\\ { \text{Solve for } d \text{ where} } \\ { d = c } \end{array} \right.$$

Solve for a, b, c, d

$$a=2\pi n_{1}+\arccos(\frac{1}{4})\text{, }n_{1}\in \mathrm{Z}\text{, }b=2\pi n_{1}+\arccos(\frac{1}{4})\text{, }n_{1}\in \mathrm{Z}\text{, }c=2\pi n_{1}+\arccos(\frac{1}{4})\text{, }n_{1}\in \mathrm{Z}\text{, }d=2\pi n_{1}+\arccos(\frac{1}{4})\text{, }n_{1}\in \mathrm{Z}$$

$$a=2\pi n_{2}+2\pi -\arccos(\frac{1}{4})\text{, }n_{2}\in \mathrm{Z}\text{, }b=2\pi n_{2}+2\pi -\arccos(\frac{1}{4})\text{, }n_{2}\in \mathrm{Z}\text{, }c=2\pi n_{2}+2\pi -\arccos(\frac{1}{4})\text{, }n_{2}\in \mathrm{Z}\text{, }d=2\pi n_{2}+2\pi -\arccos(\frac{1}{4})\text{, }n_{2}\in \mathrm{Z}$$