1) sin945 - tg45=
-√2 - 1 =
-√2 - 2 2 2sin945=sin(360*2+225)=sin225=sin(180+45)=-sin45=
-√2 22) ctgx=2cosx
cosx - 2cosx=0sinx
cosx-2cosx sinx =0 sinxsinx≠0x≠πncosx-2cosx sinx=0cosx(1-2sinx)=0cosx=0 1-2sinx=0x=π/2 +πn -2sinx=-1 sinx=1/2 x=(-1)^n * π/6 +2πnОтвет: π/2 +πn; (-1)^n * π/6 + 2πn3) sin2x - sin3x=02 sin
2x-3x cos
2x+3x =0 2 2sin (-x/2) cos 2.5x =0-sin(x/2) cos 2.5x=0sin (x/2) =0 cos 2.5x=0x/2 =πn 2.5x=π/2 + πnx=2πn x=(π/2) : (5/2) + πn : (5/2) x=π/5 +
2πn 5 x=π/5 (1+2n)Ответ: 2πn; π/5 (1+2n)