Selena is standing on a rock cliff that is 52 feet high. she tosses a pebble upward over the edge, where it hits the top of a 12 foot high boulder. the quadratic equation that models the path of the pebble is given below. how long did it take for the pebble to hit the top of the boulder? p(t)=-16t^2+12t+52

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.

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,

126.66 m²

step-by-step explanation:

the pertinent area formula is a = πr², where r is the radius.

here, a = π(6.35 m)² = 40.32π, or approximately 126.66 m²