Гипотенуза = 18.5 * 2 = 37
Теорема косинусов
37^2 = (12^2 + a^2) - 2*12*a * cos 90
cos 90 = 1
37^2 = 12^2 + a^2
a^2 = 37^2 - 12^2 = 1369 - 144 = 1225
a = √1225 = 35
Ответ: 35
<span>sinx/2*sin3x/2=1/2
1/2[cos(x/2 - 3x/2) - cos(x/2 + 3x/2)] = 1/2
cos(x) - cos(2x) = 1
применяем формулу: (cos2x = 2</span>cos²x - 1)<span>
2cos</span>²x - cosx = 0
cosx(2cosx - 1) = 0
1) cosx = 0
x₁ = π/2 + πk, k∈Z
2) 2cosx - 1 = 0
cosx = 1/2
x = (+ -)arccos(1/2) + 2πn, n∈Z
x₂ = (+ -)(π/3) + 2πn, n∈Z
<span>
</span>
Как-то так...........................
1) (-1)^5= -1
2) 3^4= 81
3) (-2,7)^4= 53,1441
4) (-2)^3= -8
5) (-5)^0= 1
6) (-7)^8= 5764801
4-1-5-3-2-6