ОДЗ 37х+2>0 37x>-2 x>-2/37
log37 (37x+2)<=log37 (37)
37x+2<=37
37x<=35
x<=35/37
(-2/37;35/37]
Cos x/3>V3/2
X/3=+-arccosV3/2+2Пk;k€Z
X/3=+-П/6+2Пk;k€Z
X=+-П/2+6Пk;k€Z
-2x^2+4ax+7=15 2x^2 -4ax+8=0 x^2-2ax+4=0 D= корень(a^2-4)=0 a=2
Cos(x+π/6)=-√3/2
x+π/6=-5π/6+2πk U x+π/6=5π/6+2πk
x=-π+2πk U x=2π/3+2πk,k∈z
tg3x=√3
3x=π/3+πk
x=π/9+πk/3,k∈z