A lighthouse is located on an island 7 miles from the closest point on a straight shoreline. If the lighthouse light rotates clockwise at a constant rate of 5 revolutions per minute, how fast does the beam of light move across the
shore when it is 4 miles from the point on the shore closest to the island?

Step-by-step explanation:

We are given that

Distance of lighthouse from  closest point P=7 miles

Using the formula

Differentiate w.r.t time

Using the formula

x=4 miles

Substitute the value

none of the above.

for one of the equations to be used in the process, there has to be a term in the equation since squared is .

since there is only a term in the first equation, we cannot derive a from completing the square.

solving with completing the square

17 1/3

step-by-step explanation: