Question

Помогите вычислить:
cos510° - sin1200° - tg1005°

Answer 1

сos(360+150)-sin(1080+120)-tg(900+105)=cos150-sin120-tg105=
=cos(180-30)-sin(90+30)-tg(60+45)=
=-cos30-cos30-(tg60+tg45)/(1-tg60*tg45)=-2*√3/2-(√3+1)/(1-√3)=
=-√3-(√3+1)(√3+1)/[(1-√3)(1+√3)=-√3-(3+2√3+1)/(1-3)=
=-√3+(4+2√3)/2=-√3+2+√3=2