Science:Math Exam Resources/Courses/MATH102/December 2014/Question A 05
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Question A 05 

The model given below on the left has been suggested for the spread of HIV within the immune system of an infected person. is the density of healthy immune cells, is the density of HIVinfected immune cells and is the density of virus in the blood of a patient. Which of the options on the right gives a correct interpretation of some part of the model?

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Hint 

What does it mean to have a positive/negative term in the right hand side of a differential equation? 
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Solution 1 

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Please rate my easiness! It's quick and helps everyone guide their studies. By observing the three given differential equations, we have the following interpretations
Thus the correct statement is (b). 
Solution 2 

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Please rate my easiness! It's quick and helps everyone guide their studies. Another way through which this question can be solved involves analyzing the relationship between the variables of the equations.
The correct statement is therefore b). 