Cos(3x+π/6)=-√3/2
3x+π/6=-5π/6+2πk U 3x+π/6=5π/6+2πk
3x=-π+2πk U 3x=2π/3+2πk
x=-π/3+2πk/3 U x=2π/9+2πk/3,k∈z
(0,3a⁵+0,5b²)³= (0,3а⁵)³+3*(0,3а⁵)² *0,5b²+3*0,3a⁵ *(0,5b²)²+(0,5b²)³=
= (3/10 a⁵)³+3*(3/10 a⁵)² * 1/2 b²+3 * 3/10 a⁵ *(1/2 b²)²+(1/2 b²)³=
= 27/1000 a¹⁵+3 * 9/100 a¹⁰ * 1/2 b²+3 * 3/10 a⁵ * 1/4 b⁴+ 1/8 b⁶=
=27/1000 a¹⁵+27/200 a¹⁰ b²+3 * 9/10 a⁵b⁴+ 1/8 b⁶