-4sin(3x/4-pi/4)>-2√2
Sin(3x/4 - π/4) < √2/2 -5π/4 + 2πk < 3x/4 - π/4 < π/4 + 2πk , k ∈Z<br>-5π/4 + π/4+ 2πk < 3x/4 < π/4 + π/4 + 2πk , k ∈Z<br>-π + 2πk < 3x/4 < π/2 + 2πk , k ∈Z<br>-4π/3 + 8πk/3 < x < 4π/3 + 8πk/3 , k ∈Z