A particle moves in a straight line under a force such that its displacement

Question

s(t), in metres, at time t seconds, is given by s(t) = t3 − 5t2 + 3t +15
Find the time at which the particle is at rest?

Answer 1

just set ds/dt=0 That is,

3t^2 - 10t + 3 = 0
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