Let $\small{s = \large{\frac{30}{t^{2}+18}}}$ be the position function of a particle moving along a coordinate line, where $\small{s}$ is in feet and $\small{t}$ is in seconds.

(a) Find the maximum speed of the particle for $\small{t \ge 0}$. If appropriate, leave your answer in radical form.

Speed (ft/sec) :

(b) Find the direction of the particle when it has its maximum speed.