1) 2sin x cos x -3sin x cos² x = 0 sin x cos x(2 - 3cos x ) = 0 sin x = 0 cos x = 0 2 - 3cos x = 0 x = πn,n∈z x = π/2 + πk,k∈z 3cos x = 2 cos x = 2|3 x = +-arccos2/3 + 2πm, m∈z2)sin 4x - sin 2x = 0 2sin x cos 3x = 0 sin x = 0 или cos 3x = 0 x = πn,n∈z 3x = π/2 + πk,k∈z x = π/6 + πк/3, к∈z 3) cos 2x + cos²x = 0 2cos² x -1 +cos² x = 0 cos² x -1 = 0 cos ² x = 1 a) cos x = 1 б) cos x = -1 x = 2πk, k∈z x = π +2πn, n∈z 4) sin 2x - cos²x = 0 2sin x cos x - cos²x = 0 cos x(2sin x -cos x) = 0 cos x = 0 или 2sin x - cos x = 0| : cos x≠0 x = π/2 + πк,к∈z 2tg x -1 = 0 2tg x = 1 tg x = 1/2 x = arctg 1/2 + πn, n∈z
[tex] \sqrt{0.81 -
36} = 0.9 - 6 = - 5.1[/tex]
[tex] \sqrt{2 \times 7} \times 6 \sqrt{2} - \sqrt{6} = \\ 6 \times \sqrt{2} \times \sqrt{2} \times \sqrt{7} - \sqrt{6} = \\ 12
\sqrt{7} - \sqrt{6} [/tex]
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