Question

Помогите решить, пожалуйста!

Answer 1

а) ...=cos(π/15 + 4π/15) /sin(0,3π+0,2π)=cos(π/3) / sin (π/2)= 1/2  : 1 = 0,5
б) ...= tg(2π/3 - 5π/12)= tg(π/4)=1
в) ...=tg (π/10+3π/20)= tg (π/4)= 1
г) ...= - sin (5π/18 -π/9) / cos(5π/12+7π/12) = - sin(π/6) / cos (π) = -1/2 : -1 =1/2