Find the maximum depth using the given function.
Suppose the function d(t) = t2 - 14t models the depth of a scuba diver at time t, as she dives underwater from a steep shoreline, reaches a centa depth, and swims back to the surfaces.
a. What is her depth after 4 sec? After 6 sec?
b. What was the maximum depth of the dive?
c. How many seconds was the diver beneath the surface?