1)=sin(π/18+π/9)=sinπ/6=1/2
2)=sin(π/36+35π/18)=sin71π/36=sin(2π-π/36)=-sinπ/36
10,АВС=АСД
11,АВЕ=ДСЕ
12,АВМ=МСВ
Х= π/4-у ; tg(π/4-y -tgy ) 1/6; tgπ/4 -tgy -tgy =1/6; -2tgy= 1/6-1; -2tgy = -5/6; tgy= -5/6÷(-2)= 5/12; y = arctg5/12 + kπ;k∈Z; x= π/4 - arctg5/12+kπ; k∈Z.
A) 3a*(z+2c-3b)
б) xy*(3*x^2-4*y^2)