1)Sin5x = -sinx
Sin5x + sinx = 0
2*[sin(5x + x)/2]*[cos(5x - x)/2] = 0
[sin(6x)/2]*[cos(4x)/2] = 0
[sin(3x)]*[cos(2x)] = 0
a) sin3x = 0
3x = πn, n∈Z
x1 = πn/3, n∈Z
b) cos2x = 0
2x = π/2 + πk, k∈Z
x2 = π/4 + πk/2, k∈Z
2) sin(x/2)*sinx = 0
a) sin(x/2) = 0
x/2 = πk, k∈Z
x1 = 2πk, k∈Z
b) sinx = 0
x2 = πn, n∈ Z
<span>(7/8)^2+cos^2x=1 + cos x = корень из 15/8</span>
8х+11-13=9х-5
8х-9х= -5-11+13
-х= -3
х=3