The formula for the circumference of a circle is 4072-01-01-03-00_files/i0150000.jpg . determine the circumference when the radius r is 10 cm.

David estimated he had about 20 fish in his pond. a year later, there were about 1.5 times as many fish. the year after that, the number of fish increased by a factor of 1.5 again. the number of fish is modeled by f(x)=20(1.5)^x. create a question you could ask that could be answered only by graphing or using a logarithm.