Question

Вычислить:
1. cos(19π/3)
2. tg(31π/6)
3. ctg (13π/4)

Answer 1

1) $cos \frac{19\pi }{3} = cos 6\frac{\pi }{3} = cos \frac{\pi }{3} = \frac{1}{2}$

2) $tg \frac{31\pi }{6} = tg 5\frac{\pi }{6} = tg \frac{\pi }{6} = \frac{\sqrt{3} }{3}$

3) $ctg \frac{13\pi }{4} = ctg 3\frac{\pi }{4} = ctg \frac{\pi }{4} = 1$

Answer 2

1. 1/2;

2. √3/3;

3. 1.

Пошаговое объяснение:

1. cos(19π/3) = cos (6π + π/3) = cos(π/3) = 1/2;

2. tg(31π/6) = tg(5π + π/6) = tg(π/6) = √3/3.

3. ctg (13π/4) = ctg(3π + π/4) = ctgπ/4 = 1.