Решите тригонометрическое уравнение 99 отдала cosx/4×sinπ/5-sinx/4×cosπ/5=√2/2

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Sinxcosy-cosxsiny=sin(x-y)
cosx/4*sinπ/5-sinπ/4*cosπ/5=0
sin(π/5-x/4)=√2/2
-sin(x/4-π/5)=√2/2
sin(x/4-π/5)=-√2/2
x/4-π/5=(-1)^(n+1)*π/4+πn,n∈z
x/4=(-1)^(n+1)*π/4+π/5+πn,n∈z
x=(-1)^(n+1)*π+4π/5+4πn,n∈z