Jawabanmu

2014-08-25T04:45:48+07:00
R=6t-3t2
V(t=3)=18-27
V(t=3)=(-9 )m/s
2 5 2
2014-08-25T04:56:41+07:00
R=3t²-t³= 2.3t²⁻¹-3.1t³⁻¹= 6t-3t²
V=6t.3t²
  =6(3)-3(3)²
  =18-27= -9 m/s