Sample Problem

The width w in centimeters of a tortoise can be modeled by the function

w = 119 - 77e-0.178t where t is the tortoise’s age in years. Graph this model and use the graph to estimate the width of a tortoise that is 3 years old. Round your answer to the nearest whole centimeter.

Width = cm


The trace feature on the graph tells us that when t = 3, w ≈ 74cm.