Sin(x - 2) = sin x - sin 2 sin x*cos 2 - cos x*sin 2 = sin x - sin 2 0 = sin x*(1 - cos 2) + cos x*sin 2 - sin 2 Переходим к половинным аргументам 2sin(x/2)*cos(x/2)*(1 - cos 2) + sin 2*(cos^2(x/2) - sin^2(x/2)) - - sin 2*(cos^2(x/2) + sin^2(x/2)) = 0 -sin^2(x/2)*(sin 2 + sin 2) + 2sin(x/2)*cos(x/2)*(1 - cos 2) + + cos^2(x/2)*(sin 2 - sin 2) = 0 -2sin 2*sin^2(x/2) + 2sin(x/2)*cos(x/2)*(1 - cos 2) = 0 2sin(x/2)*(cos(x/2)*(1 - cos 2) - sin(x/2)*sin 2) = 0 1) sin(x/2) = 0; x/2 = pi*k; x = 2pi*k 2) cos(x/2)*(1 - cos 2) - sin(x/2)*sin 2 = 0 cos(x/2)*(1 - cos 2) = sin(x/2)*sin 2 tg(x/2) = (1 - cos 2)/sin 2 x/2 = arctg((1 - cos 2)/sin 2) + pi*n x = 2arctg((1 - cos 2)/sin 2) + 2pi*n Еще подходит x = 2 sin (2 - 2) = sin 2 - sin 2 sin 0 = 0
Sin(x - 2) = sin x - sin 2 sin x*cos 2 - cos x*sin 2 = sin x - sin 2 0 = sin x*(1 - cos 2) + cos x*sin 2 - sin 2 Переходим к половинным аргументам 2sin(x/2)*cos(x/2)*(1 - cos 2) + sin 2*(cos^2(x/2) - sin^2(x/2)) - - sin 2*(cos^2(x/2) + sin^2(x/2)) = 0 -sin^2(x/2)*(sin 2 + sin 2) + 2sin(x/2)*cos(x/2)*(1 - cos 2) + + cos^2(x/2)*(sin 2 - sin 2) = 0 -2sin 2*sin^2(x/2) + 2sin(x/2)*cos(x/2)*(1 - cos 2) = 0 2sin(x/2)*(cos(x/2)*(1 - cos 2) - sin(x/2)*sin 2) = 0 1) sin(x/2) = 0; x/2 = pi*k; x = 2pi*k 2) cos(x/2)*(1 - cos 2) - sin(x/2)*sin 2 = 0 cos(x/2)*(1 - cos 2) = sin(x/2)*sin 2 tg(x/2) = (1 - cos 2)/sin 2 x/2 = arctg((1 - cos 2)/sin 2) + pi*n x = 2arctg((1 - cos 2)/sin 2) + 2pi*n Еще подходит x = 2 sin (2 - 2) = sin 2 - sin 2 sin 0 = 0
3 корня x={0; 2; 2π}
Объяснение:
sin(x-2)=sinx-sin 2
sin(x-2)-sinx=-sin 2
2sin(-1)cos(x-1)=-2sin1cos1
-2sin1cos(x-1)=-2sin1cos1
cos(x-1)=cos1
x-1=±arccos(cos1)+2kπ
x-1=±1+2kπ
x=1±1+2kπ
1) x=1-1+2kπ=2kπ
x∈[0;2π]⇒x={0;2π}
2) x=1+1+2kπ=2+2kπ
x∈[0;2π]⇒x=2