ulikejazz69 ulikejazz69 26-10-2020 Mathematics contestada Please Help A particle moves according to a law of motion s = f(t) = t3 - 12t2 + 45t, t 0, where t is measured in seconds and s in feet. a.When is the particle speeding up? (????,????)U(????,????) b.When is it slowing down? (????,????)U(????,????)