sin( 3x + P/4 ) = -1

sim(3x + π/4) = -13x + π/4 = - π/2 + 2πk, k∈Z3x = - π/2 - π/4 + 2πk, k∈Z3x = - 3π/4 + 2πk, k∈Zx = - π/4 + 2πk/3, k∈Z