แก้โจทย์ {l}{13sin(A)=12}{a=sec(A)-tan(A)}{b=a}{c=b}{text{Solvefor}dtext{where}}{d=c}

$$\left. \begin{array} { l } { 13 \sin(A) = 12 }\\ { a = \sec(A) - \tan(A) }\\ { b = a }\\ { c = b }\\ { \text{Solve for } d \text{ where} } \\ { d = c } \end{array} \right.$$

หาค่า A, a, b, c, d

$$A=2\pi n_{1}+\arctan(\frac{12}{5})\text{, }n_{1}\in \mathrm{Z}\text{, }a=\frac{1}{5}=0.2\text{, }b=\frac{1}{5}=0.2\text{, }c=\frac{1}{5}=0.2\text{, }d=\frac{1}{5}=0.2$$

$$A=2\pi n_{2}+\pi -\arctan(\frac{12}{5})\text{, }n_{2}\in \mathrm{Z}\text{, }a=-\frac{1}{5}=-0.2\text{, }b=-\frac{1}{5}=-0.2\text{, }c=-\frac{1}{5}=-0.2\text{, }d=-\frac{1}{5}=-0.2$$