151.
ա) sin(-30)=-1/2
բ)cos(-π/3)= 1/2
գ)tg(-π/4)=-1
դ)tg(-5π/6)=-√3/3
ե)ctg(-135)=1
զ)ctg(-2π/3)=√3/3
152.
ա)
sin(25π/6)=1/2
cos(25π/6)=√3/2
tg(25π/6)=√3/3
ctg(25π/6)=√3
բ)
sin(840)=√3/2
cos(840)=-1/2
tg(840)=-√3
ctg(840)=-√3/3
գ)ctg(-420) = ctg(-60) = -ctg60 = -√3/3
դ) ctg(-3π/4) = -ctg(3π/4) = 1
ե) ctg(-5π/6) = -ctg(5π/6) = √3
զ) ctg(11π/4) = ctg(3π/4) = -√3
Էրիկ Գևորգյան 