Сначала:
arcCos√3/2 = π/6
arcSin√2/2 = π/4
arc tg √3 = π/3
Теперь решаем:
а) Cos(π + π/6) = -Сosπ/6 = -√3/2
б) Cos(π/2 - π/3) =Sinπ/3 = √3/2
в) 8Sin x = 7Cos x |: Сosx ≠0
8tg x = 7
tgx = 7/8
x = arctg(7/8) + πk, k∈Z
..............................................................
Πх/6 = arctg√3 + πk , k ∈ Z
πx/6 = π/3 + πk , k ∈ Z
x/6 = 1/3 + k , k∈Z
x = 2 + 2k , k ∈Z
x = -2
........
3(а+1)+2а(1+а)=(3+2а)(а+1) при а= -2/7 подставляем:
(3-
)(1-2/7); получаем: 17/7 * 5/7= 85/49
<span>During the week I always have to get up early for work so on Sunday I love to wake up late, usually around 9am and then get up 30 minutes later.</span><span>The first thing I do is switch on the coffee maker. No instant coffee for me today! On Sundays I always take the time to make some good coffee. While that's getting ready, I quickly throw onsome clothes and pick up a newspaper from the local shop.</span><span>With my coffee and paper, I spend the rest of the morning on the sofa. Sometimes I even turn offmy phone for a couple of hours so no one calls me.</span><span>Later in the day, I like to hang out with friends over lunch and catch up with their news and gossip.
</span><span>
</span><span>All in all, that's my idea of a good day!
ну вот так как то))
</span>