Вычислите sin 13п/12+sin 7п/12-cos 5п/12+cos п\12

Question

Вычислите sin 13п/12+sin 7п/12-cos 5п/12+cos п\12

Answer 1

2sin(5π/6)cos(π/4)-2sInπ/4sin(-π/6)=2sinπ/6*cosπ/4+2sinπ/4sinπ/6=
=2*1/2*√2/2+2*√2/2*1/2=√2