SOLUTION: The formula below can be used to find the number of milligrams D of a certain drug that is in a patients bloodstream h hours after the drug has been administered. D = 5e^(-0.37

Algebra ->  Test -> SOLUTION: The formula below can be used to find the number of milligrams D of a certain drug that is in a patients bloodstream h hours after the drug has been administered. D = 5e^(-0.37      Log On


   

Question 116631:
The formula below can be used to find the number of milligrams D of a certain drug that is in a patients bloodstream h hours after the drug has been administered.
D = 5e^(-0.37h)
When the number of milligrams reaches 2, the drug is to be administered again. What is the time between injections?
hours

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
setting D equal to 2 and dividing by 5 gives .4=e^(-0.37h)

taking the natural log gives ln(.4)=-0.37h ___ dividing by -0.37 gives (ln(.4))/(-0.37)=h