Решить вычислите : а) tg225cos330ctg120sin240 б)ctg5pi/3*sin3pi/4*tg5pi/6*cos4pi/3

A) tg(180+45)cos(360-30)ctg(90+30)sin(270-30)=-tg45cos30(-tg30)(-cos30)=-1·√3/2·1/√3·√3/2=-√3/4
б)ctg(2π-π/3)sin(π-π/3)tg(π-π/6)cos(π+π/3)=-ctgπ/3·sinπ/3·(-tgπ/6)·(-cosπ/3)=-1/√3·√3/2·1/√3·1/2=-1/(4√3)=- √3/12