√2sin(3П/2-х)*sinx=cosx
-√2cosx*sinx-cosx=0
-cosx(√2sinx+1)=0
cosx=0⇒x=π/2+πn,n∈z
-5π≤π/2+πn≤-4π
-π/2-5π≤πn≤-π/2-4π
-5,5≤n≤-4,5
n=-5⇒x=π/2-5π=-9π/2
sinx=-1/√2
x=-π/4+2πk,k∈z U x=5π/4+2πm,m∈z
-5π≤-π/4+2πk≤-4π
-19/4≤2k≤-15/4
-19/8≤k≤-15/8
k=-2⇒x=-π/4-4π=--17π/4
-5π≤5π/4+2πm≤-4π
-25/4≤2m≤-21/4
-25/8≤m≤-21/8
m=-3⇒x=5π/4-6π=-19π/4
x=-19π/4 наим
4*(-19π/4):π=-19