Solve the problem.
-The formula D $$\mathrm { D } = 8 \mathrm { e } ^ { - 0.04 h }$$ can be used to find the number of milligrams D of a certain drug in a patient's bloodstream h hours after the drug has been given. When the number of milligrams reaches 4, the drug is to be
Given again. What is the time between injections?
A) 34.66 hrs
B) 17.33 hrs
C) 51.99 hrs
D) 20.47 hrs

Question

Quizplus · Accepted Answer

To find the time between injections, set D = 4 and solve for h:  4 = 8e^(-0.04h)  0.5 = e^(-0.04h)  Taking the natural logarithm of both sides:  ln(0.5) = -0.04h  h = ln(0.5) / -0.04 ≈ 17.33 hrs.

Solve the Problem D=8e−0.04h\mathrm { D } = 8 \mathrm { e } ^ { - 0.04 h }D=8e−0.04h

Solve the Problem $\mathrm { D } = 8 \mathrm { e } ^ { - 0.04 h }$