Розв'яжіть {left(12/13right)}^2+cos(θ)*cos(θ)=1

$${ \left( \frac{ 12 }{ 13 } \right) }^{ 2 } + \cos ( \theta ) \times \cos ( \theta ) =1$$

Знайдіть θ (complex solution)

$$\theta =\pi n_{1}+\arctan(\frac{12}{5})\text{, }n_{1}\in \mathrm{Z}$$

$$\theta =\pi n_{2}+\pi -\arctan(\frac{12}{5})\text{, }n_{2}\in \mathrm{Z}$$

Знайдіть θ

$$\theta =\pi n_{1}+\arccos(\frac{5}{13})\text{, }n_{1}\in \mathrm{Z}$$

$$\theta =\pi n_{2}+\pi -\arccos(\frac{5}{13})\text{, }n_{2}\in \mathrm{Z}$$