A=v`(t)=-12sin(3t-π/6)
x(t)=F(v)=4/3*sin(3t-π/6)+C
4/3*sin(π-π/6)+C=5/3
4/3*1/2+C=5/3
C=5/3-2/3=1
x(π/3)=4/3*sin(3t-π/6)+1
v(π/3)=4cos5π/6 =-4*√3/2=-2√3
a(π/3)=-12sin5π/6=-12*1/2=-6
-1 ≤ Cosx ≤ 1 | * 3
-3 ≤ 3Cosx ≤3 | - 4
-7 ≤ 3Cosx - 4 ≤ -1
3t²-5t²-11t-3t²+5t+11=-5t²-6t+11
-5t²-6t+11=0
D=36-4*(-5)*11=36+220=256
D=√256=16
Ответ:(1; 2 2/10)