What is the definition of the cosine function in relation to a right triangle using the adjacent side and hypotenuse?

22) In a triangle \( A B C \) if: \( 3 \sin A=2 \sin B=4 \sin C \), then \( a: b: c= \)

6) \( \sin x \cdot \operatorname{tg} \frac{x}{2}=0 \)

13. а) Решите уравнение \( \sin 2 x \sin x+\sqrt{2} \cos ^{2} x=\sqrt{2} \). б) Укажите корни уравнения, принадлежащие отрезку \( \left[\frac{3 \pi}{2} ; 3 \pi\right] \)

If the adjacent side measures 8 meters and the angle opposite to it is 45 degrees, calculate the length of the opposite side using trigonometric ratios.

Найдите множество значений функции \( y=4 \cos x-3 \) \( y \in(-1 ; 1) \)