28.3. Вычислите: 1) 2sin22'30' • cos7'30'; 2) 2cos7'30' • sin52'30';

28.3. Решение:

1. 2sin22'30' • cos7'30' = sin(2 • 22'30') = sin(45°) = √2 / 2;
2. 2cos7'30' • sin52'30' = cos(2 • 7'30') = cos(15°) = √3 / 2.