若cos2x/sin(x-π/4)=-√2/2,则√2sin(x+π/4)的值为

若cos2x/sin(x-π/4)=-√2/2,则√2sin(x+π/4)的值为
若cos2x/sin(x-π/4)=-√2/2,则√2sin(x+π/4)的值为

若cos2x/sin(x-π/4)=-√2/2,则√2sin(x+π/4)的值为
设x+π/4=a
cos2x/sin(x-π/4)=-√2/2,
即cos[2a-π/2】/sin(a-π/2)=-√2/2,
得sin[2a】/cosa=√2/2,
2sina==√2/2,

sina==√2/4
√2sin(x+π/4)=√2sina=1/2

三分之二倍根号二