Recall that to evaluate a function at a given value, we substitute the variable with the given value.
Since h represents the number of hours after the drug is injected, then the initial amount of drug is at h=0. Evaluating D(h) at h=0 we get:
[tex]D(0)=5e^{-0.45*0}=5e^0=5.[/tex]
Therefore the initial amount of drug in the blood is 5 milligrams.
Evaluating D(h) at h=8 we get:
[tex]\begin{gathered} D(8)=5e^{-0.45*8}=5e^{-3.6} \\ \approx0.14. \end{gathered}[/tex]
Answer:
[tex]\begin{gathered} Initial\text{ }amount:\text{ }5milligrams. \\ Amount\text{ }after\text{ }8\text{ }hours:\text{ }0.14milligrams. \end{gathered}[/tex]
