Two cyclists start together along a straight road. Their displacements (in metres) after t seconds are
Cyclist A: sA(t)=t3−6t2+9t,
Cyclist B: sB(t)=t2−2t+4.
At what smallest positive time will they have the same instantaneous velocity?
a) 2s
b) 1s
c) 311s
d) 0.5s