Sin4xcosx-cos4xsinx больше -√2/2

Решение Sin4xcosx-cos4xsinx>-√2/2 sin(4x - x) > - √2/2 - arcsin( -√2/2) + 2πk < 3x < π + arcsin(- √2/2) + 2πk, k ∈ Z π/4 + 2πk < 3x < π - π/4  + 2πk, k ∈ Z π/4 + 2πk < 3x < 3π/4  + 2πk, k ∈ Z π/12 + 2πk/3 < 3π  + 2πk/3, k ∈ Z