Например так
17 17 17 17 16 16
Sin(51)cos(21)−cos(51)sin(21)=1/2(Sin(51 -21) + Sin(51+21)) − 1/2(Sin(51+21) - Sin(51+21))=1/2(Sin(30) + Sin(72)) − 1/2(Sin(72) - Sin(30))=1/2(Sin(30) + Sin(72) − Sin(72) + Sin(30))=1/2(Sin(30) + Sin(30))= 1/2(1/2 + 1/2)=1/2
ответ после третего 1 метр
делаем припомащи прапорциии
1) 2-------100
х-------- 80
2) 1,6 ------100
х --------80
3) 1,28----- 100
х----80
1. <span>(1-4sinx*cosx)*(sin6x-1)=0</span>
<span>(1-4sin(x)cos(x)) (sin(6x)-1)=0</span>
<span>(sin(6x)-1) (-(4sin(x) cos(x)-1))=0</span>
<span>sin(6x) + 4sin(x)cos(x) - 4sin(6x)sin(x)cos(x)-1=0</span>
<span>2sin(2x)+sin(6x) - cos(4x)+cos(8x) -1=0</span>
<span>x≈2.(3.14159n - 1.4399) n ∈ Z</span>
<span>x≈2.(3.14159n - 0.916298) n ∈ Z</span>
<span>x≈2.(3.14159n + 0.1309 ) n ∈ Z</span>
<span>x≈2.(3.14159n + 0.654498 ) n ∈ Z</span>
<span>x≈0.0833333(12.5664n + 3.14159 ) n ∈ Z</span>