3. b) Environmentalists discover what appears to be an oil leak rising to the surface of a lake. When they first discover the circular substance, it has a radius of 2 feet. Every minute that passes, the radius grows by three-quarters of an inch. [4 pts] Create a linear function which gives the radius of the circle in inches after t minutes. Call this function r(t). [2 pts] The Area of a circle is A = nrz. With this knowledge, use composition of functions to represent the Area of the circular substance in square inches after t minutes. Call this function A(t). [3 pts] Use your answer to part b to find the area of the circular substance after a half hour has passed. Round your final answer to the nearest whole number and include appropriate units