420
sin (-330°)=-sin330°=-sin (360°-30°)=sin30°=1/2=0,5
cos(-120°)=cos120°=cos(180°-60°)=-cos60°=-1/2=-0,5
tg(-240°)=-tg240°=-tg(180°+60°)=-tg60°=-√3
ctg(-330°)=-ctg 330°=-ctg(360°-30°)=-ctg30°=-√3
Поэтому ответ в задании
0,5²-(-0,5)²-(-√3)²+(-√3)²=0
421
sin(π/2 - α)=cosα
cos( π - α)=-cosα
tg( π - α)= - tgα
ctg(3π/2 +α)=- tgα
Ответ cosα-(-cosα)-tgα-(-tgα)=2cosα
422
cos(-5π/6)=cos(5π/6)=cos(π - π/6)=-cosπ/6
cos(11π/6)=cos (12π/6 - π/6)=cosπ/6
tg(5π/6)=-tgπ/6=-√3.3
sin(5π/3)=sin(π + 2π/3)=- sin2π/3=-sinπ/3=-√3/2
cosπ=-1
cos(-4π/3)=cos(4π/3)=cos(π + π/3)=-cosπ/3=-1/2
ctg2π/3=ctg(π - π/3)=-ctgπ/3=-√3/3
Ответ -1 - (-√3/3)·(-√3/2)/(-1)+(-1/2)·(-√3/3)=-1+1/2+√3/6=1/2+√3/6=(3+√3)/6