Срочно ! Помогите пожалуйста

Question

Срочно ! Помогите пожалуйста

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Answer 1

1.  cos125° = cos(180° – 55°) = - cos 55°

2.  sin 5π/6 = sin (π – π/6)  = sin π/6

3.  sin 70° = sin(90° – 20°) = cos 20°

4.  cos π/3 = cos(π/2 – π/6) = sin π/6

cos 2π/3 = cos (π – π/3) = - cos π/3 = - 1/2

cos 5π/6 = cos (π – π/6) = - cos π/6 = -

 

Answer 2

Сos125=cos(180-55)=-cos55
sin5π/6=sin(π-π/6)=sinπ/6
sin70=sin(90-20)=cos20
cosπ/3=cos(π/2-π/6)=sinπ/6
cos2π/3=cos(π-π/3)=-cosπ/3
cos5π/6=cos(π-π/6)=-cosπ/6