(c) $y = a + bt + ct^{2} - dt^{4}$ $\therefore v = \frac{dy}{dt} = b + 2ct - 4dt^{3}$ and $a = \frac{dv}{dt} = 2c - 12dt^{2}$ Hence, at $t = 0,\ v_{initial} = b$ and $a_{initial} = 2c$
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Ph.D. in Physics with 19+ years of teaching experience.