Sinπx = Cosπx | : Сosπx
tgπx = 1
πx = π/4 + πk , k ∈ Z
x = 1/4 + k , k ∈Z
Ответ: 1/4
2) Sinx > 1/2 и -π/4 < x < π/3
Ответ: π/6≈3,14:6 ≈0,52
3) Sin(α + β) -2CosαSinβ =SinαCosβ + CosαSinβ b-2CosαSinβ =
=SinαCosβ - CosαSinβ = Sin(α -β) = Sin(73° - 43°) = Sin30° = 1/2