แก้โจทย์ cscθ=-frac{sqrt{13}}{2}

$$\csc \theta = - \frac { \sqrt { 13 } } { 2 }$$

หาค่า θ (complex solution)

$$\theta =2\pi n_{1}+\pi +\arctan(\frac{2}{3})\text{, }n_{1}\in \mathrm{Z}$$

$$\theta =2\pi n_{2}+2\pi -\arctan(\frac{2}{3})\text{, }n_{2}\in \mathrm{Z}$$

หาค่า θ

$$\theta =2\pi n_{1}+\arcsin(\frac{2\sqrt{13}}{13})+\pi \text{, }n_{1}\in \mathrm{Z}$$

$$\theta =2\pi n_{2}-\arcsin(\frac{2\sqrt{13}}{13})+2\pi \text{, }n_{2}\in \mathrm{Z}$$