Chapter A.4, Problem 78E

To determine

To find: the conclusions can draw from the bar graph.

Explanation of Solution

Given information:

The mathematical model

  $P=100\left(\frac{t^2-t+1}{t^2+1}\right),t\ge 0$

Gives the percent $P$ of the normal level of oxygen in a pond, where $t$ is the time after organic waste is dumped into the pond. The graphs shows the situation.

Calculation:

Consider the bar graph provided in the book on page number A44 below question number 80.

The bar graph represents that when $t=0$ or at the beginning the percent of normal oxygen level is 100. When $t=1$ the percent of normal oxygen level is 50 and when $t=2$ the percent of normal oxygen level is 60. After first week as the time increases the oxygen level is also increase. For larger value of $t$ the oxygen level becomes costant.

Hence you can conclude that at the beginning the oxygen level is 100, for first week the oxygen level reduced to half, after that oxygen level increases, as the value of $t$ increases the oxygen level increases comparatively slow, for higher value of $t$ the oxygen level is constant.

Use maple to draw the graph of the mathematical model $P=100\left(\frac{t^2-t+1}{t^2+1}\right),t\ge 0$ as shown below.