\( f(x)=\sin (x) \) and \( g(x)=\cos (x) \), find the composition \( f(g(x)) \) and evaluate it at \( x=\frac{\pi}{4} \)

If \( \tan \frac{a}{b}=1 \), then \( \tan \frac{2 a}{3 b}=\ldots \ldots \ldots \ldots \) \( \begin{array}{llll}\text { (a) } \frac{1}{2} & \text { (b) } \frac{1}{\sqrt{3}} & \text { (c) } \frac{2}{3} & \text { (d) } \sqrt{3}\end{array} \)

تعریف کتانژنت چیست و چگونه با مثلث راست مرتبط است؟

5.2 Determine the following with the aid of a calculator 5.2.1 \( \quad \) the size of the angle \( \alpha \). 5.2.2 the area of the \( \triangle P O X \) if it given that \( \mathrm{X}(2 ; 0) \)

3. Find the radian measure of each angle below: \( \begin{array}{llll}\text { (a) } 35^{\circ} & \text { (b) } 80^{\circ} & \text { (c) } 145^{\circ} & \text { (d) } 220^{\circ}\end{array} \)

\( \frac{\cos \theta \csc \theta}{\tan \theta} \) أي مما يأتي يكانئ العبارة