Solve, finding all solutions in \( [0,2 \pi) \) or \( \left[0^{\circ}, 360^{\circ}\right) \). \( 2 \cos x-1=-1.2814 \) The solution(s) in \( \left[0^{\circ}, 360^{\circ}\right) \) is/are \( x \approx \square \). (Type your answer in degrees. Do not include the degree symbol in your answer. Round to two decimal places as needed. Use a comma to separate answers as needed.)

اشرح كيفية إيجاد الكوسكانت لزاوية محددة استنادًا إلى أطوال الأضلاع في مثلث قائم الزاوية.

6.3 If \( \quad \tan x=m+\frac{1}{m}, 90^{\circ} \leq x \leq 270^{\circ} \) and \( m^{2}+\frac{1}{m^{2}}=1 \) Calculate the value of \( x \) without the use of a calculator.

3. Решите неравенство \[ 2 \cos \left(2 x+\frac{\pi}{3}\right) \geq 1 \]

а) \( \operatorname{tg} \frac{\alpha}{2}=\frac{1-\cos \alpha}{\sin \alpha} \);

(ii) Given that \( \frac{3 \pi}{4}<\theta<\pi \) and \( \sin 2 \theta=-\frac{3}{5} \). Find the value of \( \tan \theta \) without using a calculator.