Вычислите sin75-sin15

sinα - sinβ = 2cos((α + β)/2) · sin((α - β)/2) sin75° - sin15° = 2cos((75° + 15°)/2) · sin((75° - 15°)/2) = 2cos45° · sin30° = 2 · √2/2 · 1/2 = √2/2