Вычислите с помощью формул приведения: 1) sin 5π/4 2) cos (-7π/3) 3) tg 5π/3 4) sin 40π/3 5) ctg 1π/6

1) sin 5 * π/4 = sin (4 * π/4 + π/4) = sin (π + π/4) = - sin π/4 = - √2/2;

2) cos ( - 7 * π/3) = cos 7 * π/3 = cos (6 * π/3 + π/3) = cos (2 * π + π/3) = cos π/3 = 1/2;

3) tg 5 * π/3 = tg (6 * π/3 - π/3) = tg (2 * π - π/3) = tg ( - π/3) = - tg π/3 = - √3;

4) sin 40 * π/3 = sin (39 * π/3 + π/3) = sin (13 * π + π/3) = sin (π + π/3) = - sin π/3 = - √3/2;

5) ctg 1 * π/6 = ctg π/6 = √3.

Ответ: 1) - √2/2; 2) 1/2; 3) - √3; 4) - √3/2; 5) √3.