Question

3. sin 5a= cos 2a, 0° <a< 180°.​

Answer 1

Step-by-step explanation:

$\cos( \frac{\pi}{2} - 5 a) = \cos(2a) \\ \implies \: \frac{\pi}{2} - 5 a = 2a \\ \implies \: a = \frac{\pi}{14}$