Acircular oil spill continues to increase in size. the radius of the oil spill, in miles, is given by the function r(t) = 0.5 + 2t, where t is the time in hours. the area of the circular region is given by the function a(r) = πr2, where r is the radius of the circle at time t.

explain how to write a composite function to find the area of the region at time t.

The area at time t is given  by

Step-by-step explanation:

We know the radius of the oil spill as a function of time, and we know the area as a function of radius, and we want the area at time t. In other words we are looking for area as a function of time

We find by putting  into as a substitute to r:

Which is our answer.

$5.41

step-by-step explanation:

$20 - $14.51 = $5.49.