\( \alpha+\beta=90^{\circ} \) হলে, \( \operatorname{Sin}^{2} \alpha+\operatorname{Sin}^{2} \beta \)

The angle of depression from one mountain summit to another is \( 15.9^{\circ} \). If the two mountains differ in height by 430 metres, find the horizontal distance between the two summits, to the nearest centimetre.

2. Решите уравнение . В ответе напишите наименьший положительный корень. \( \sin \frac{\pi(4 x-3)}{4}=\frac{\sqrt{2}}{2} \)

Given that \( \theta \) is an obtuse angle and \( \operatorname{cosec} \theta=k \), express, in terms of \( k \) (a) \( \cot \theta \)

35. Diketahui segitiga ABC siku-siku di \( \mathrm{B}, \mathrm{a}=8 \mathrm{~cm} \) dan \( \mathrm{c}=6 \mathrm{~cm} \), maka nilai \( \cos A=\cdots \) a. \( \frac{4}{3} \) b. \( \frac{4}{5} \) c. \( \frac{5}{3} \) d. \( \frac{3}{5} \) e. \( \frac{3}{4} \)

a) \( \sin ^{4} x+\cos ^{2} x \cdot \sin ^{2} x-\sin ^{2} x \)