India is the second most populous country in the world with a population of about [latex]1.25[/latex] billion people in [latex]2013[/latex]. The population is growing at a rate of about [latex]1.2\%[/latex] each year.^[1] If this rate continues, the population of India will exceed China’s population by the year [latex]2031[/latex]. When populations grow rapidly, we often say that the growth is “exponential.” To a mathematician, however, the term exponential growth has a very specific meaning. In this section, we will take a look at exponential functions which model this kind of rapid growth.