21 задание,немного туплю

Question

21 задание,немного туплю

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Answer 1

Sin(15)/sin(5)-sin(75)/cos(5)=sin(15)/sin(5)-cos(15)/cos(5)=
=(sin(15)*cos(5)-cos(15)*sin(5))/(sin(5)*cos(5))=
=sin(15-5)/(1/2*sin(10))=2