Graph the relation. Is the relation a function? Why or why not? {(-1, 9), (0, -1), (-1, 4), (4, 9)} No; a domain value has two range values. Yes; there is only one domain value for each range value. Yes; there is only one range value for each domain value. No; a range value has two domain values.

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.