Answer: At , the pebble hit the top of the boulder.
Step-by-step explanation:
Since we have given that
Distance at which Selena is standing on a rock cliff = 52 feet
Height of boulder above a rock cliff = 12 foot
So, the given quadratic equation would be
First we derivative it w.r.t t,
Now, we will find the critical value,
Now, we will check whether it is maximum or not.
So, we get that it is maximum.
Hence, at , the pebble hit the top of the boulder.
