Determine whether the function represents exponential growth or decay. Write the base in terms of the rate of growth or decay, identify r, and interpret the rate of growth or decay. y= 12,600 9 10 X The function y = 12,600 represents exponential 10 Rewriting the base in terms of the rate of growth or decay results in the function y = 12,600 (*. In this function, r=which indicates that the value of y by % each time period.