1550078481-Ordinary_Differential_Equations__Roberts_

Applications of Systems of Equations 475

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S(t)

oL-.~~~~~~~~....=:::::::::;:::::;==::;~=;==;---l

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0 2 4 6 8

Figure 10 .19 A Graph of S(t), I(t), and R(t) for System (6)

for Initial Conditions (ii)

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o-+---.----r-r----.,--...-.....---r---.----r-..----.,--...-.....---r---.----r-..----.,--r---1

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s

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Figure 10. 20 A Phase-Plane Graph of I versus S for System (6)

for Initial Conditions (ii)

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