Вычислите sin120*tg225+,sin 315

Question

Вычислите sin120*tg225+,sin 315

Answer 1

Sin120°*tg225°+sin315°=sin(90°+30)*tg(180°+45°)+sin(270°+45°)=
=sin30°*tg45°-cos45°=0,5*1-√2/2=1/2-√2/2=(1-√2)/2.