แก้โจทย์ {l}{cos(A)=0.5}{a={(sqrt{2})}}{b=a}{c=b}{text{Solvefor}dtext{where}}{d=c}

$$\left. \begin{array} { l } { \cos(A) = 0.5 }\\ { a = {(\sqrt{2})} }\\ { b = a }\\ { c = b }\\ { \text{Solve for } d \text{ where} } \\ { d = c } \end{array} \right.$$

หาค่า A, a, b, c, d

$$A=2\pi n_{1}+\frac{\pi }{3}\text{, }n_{1}\in \mathrm{Z}\text{, }a=\sqrt{2}\approx 1.414213562\text{, }b=\sqrt{2}\approx 1.414213562\text{, }c=\sqrt{2}\approx 1.414213562\text{, }d=\sqrt{2}\approx 1.414213562$$

$$A=2\pi n_{2}+\frac{5\pi }{3}\text{, }n_{2}\in \mathrm{Z}\text{, }a=\sqrt{2}\approx 1.414213562\text{, }b=\sqrt{2}\approx 1.414213562\text{, }c=\sqrt{2}\approx 1.414213562\text{, }d=\sqrt{2}\approx 1.414213562$$