Solve the triangle. \( \mathrm{a}=8, \mathrm{c}=5, \mathrm{~B}=90^{\circ} \) \( \mathrm{b}=\square \) (Do not round until the final answer. Then round to the nearest tenth as needed.) \( \mathrm{C}=\square^{\circ} \) (Do not round until the final answer. Then round to the nearest degree as needed.) \( \mathrm{A}=\square^{\circ} \) (Do not round until the final answer. Then round to the nearest degree as needed.)

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

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

\begin{tabular}{|l|} 3. Решите уравнение. В ответе напишите \\ наибольший отрицательный корень. \\ \( \sin \frac{\pi(4 x+5)}{6}=-0,5 \)\end{tabular}

b) \( 3\left(\cos ^{4} x+\sin ^{4} x\right)-2\left(\cos ^{6} x+\sin ^{6} x\right)=1 \)

- \( \left|\begin{array}{l}\text { 1.Решите уравнение. В ответе напишите } \\ \text { наименьший положительный корень. } \\ \sin \frac{\pi(x+9)}{4}=-1\end{array}\right| \)