√2sin (π/4 - x/28 ) + sin x/28= - 1 помогите решить

Question

√2sin (π/4 - x/28 ) + sin x/28= - 1 помогите решить

Answer 1

√2(sinπ/4cosx/28-cosπ/4sinx/28)+sinx/28=-1
√2*√2/2(cosx/28-sinx/28)+sinx/28=-1
cosx/28-sinx/28+sinx/28=-1
cosx/28=-1
x/28=π+2πn,n∈z
x=28π+56πn,n∈z