In Exercises 33 and 34, find the zero or zeros of the given function.

Module 1 Introduction to periodic functions Example 1: High and low tides The height of tide above or below sea level, measured in feet, is a function of t, the number of hours since 6.00 am. A graph of h t( )is shown in Figure 1.1. Figure 1.1: The tide height at time t The main feature that we note about this function, is that it appears to repeat itself from approximately [0, 12] to [12, 24]. Functions that exhibit this behavior are called periodic, and will be our focus for most of MTH 112. Notice that the maximum value of the function is 20; in this application, that means that the highest the tide reaches is 20 ft above sea level. The minimum value of the function is -20 ft, which in this application means that the lowest the ti