Question

Найдите sin 150 ,cos 150,tg 150,ctg 150

Answer 1

$1)sin(180 ^{o}- alpha)=sinalpha$

$sin150^{o}=sin(180 ^{o}-30 ^{o})=sin30 ^{o}= frac{1}{2}$

$2)cos(180^{o}- alpha)=-cos alpha$

$cos150^{o}=cos(180 ^{o}-30 ^{o})=-cos30 ^{o}= -frac{sqrt{3} }{2}$

$3)tg(180^{o}- alpha)=-tg alpha$

$tg150^{o}= tg(180^{o}-30 ^{o})=-tg30^{o}=- frac{sqrt{3} }{3}$

$4)ctg(180^{o}- alpha)=-ctgalpha$

$ctg150^{o}=ctg(180 ^{o}-30 ^{o})=- ctg30^{o}=- sqrt{3}$