Объяснение:
6. sin3x = - 1/2, по таблице синусов - косинусов, sinα = -1/2, если α = 7π/6, следовательно,
3х = 7π/6 → х = 7π/6*3 = 7π/18 ≈ 7 *180°/18 = 70°
7. 2cosx = - 1 → cos x = - 1/2 → x = 2π/3 ≈2*180°/3 = 120°
8. cos (2x -π/4) = 1/2 → 2x -π/4 = π/3 → 2x = π/3 - π/4 = (4π-3π)/12 →
x = π/12*2 = π / 24 ≈ 180°/24 = 7.5°
9. 4x + π/4 = 2π/3 → 4x = 2π/3 - π/4 → ....
10. 3x/4 +π/3 = π/6 → 3х/4 = π/6 - π/3 → ...
Объяснение:
6. sin3x = - 1/2, по таблице синусов - косинусов, sinα = -1/2, если α = 7π/6, следовательно,
3х = 7π/6 → х = 7π/6*3 = 7π/18 ≈ 7 *180°/18 = 70°
7. 2cosx = - 1 → cos x = - 1/2 → x = 2π/3 ≈2*180°/3 = 120°
8. cos (2x -π/4) = 1/2 → 2x -π/4 = π/3 → 2x = π/3 - π/4 = (4π-3π)/12 →
x = π/12*2 = π / 24 ≈ 180°/24 = 7.5°
9. 4x + π/4 = 2π/3 → 4x = 2π/3 - π/4 → ....
10. 3x/4 +π/3 = π/6 → 3х/4 = π/6 - π/3 → ...