Complete question :
A therapeutic drug has the side effect of raising a patient's heart rate. The relationship between ,
the amount of the drug in the patient's body (in milligrams), and r, the patient's heart rate (in beats
per minute) is given by r(Q) = 60+ 0.2Q. Over time the level of the drug in the patient's
bloodstream changes. The amount of drug in the patient's body, Q, (in milligrams) t minutes after
the drug has been administered is given by Q(t) = 250(0.8)^t.
a. What is the heart rate of this patient 5 minutes after the drug was administered? 8 minutes?
10 minutes? 13 minutes?
Answer:
76.384 ;
68.389 ;
65.369;
62.749
Explanation:
Given function:
r(Q) = 60+ 0.2Q ; amount of drug on patient's body, Q and heart rate (r)
The amount of drug in the patient's body, Q, (in milligrams) t minutes after
the drug has been administered is given by Q(t) = 250(0.8)^t
a. What is the heart rate of this patient
5 minutes after the drug was administered?
t = 5 ; quantity of drug on patient's body ;
Q(5) = 250(0.8)^5 = 81.92
Q = 81.92
Heart rate (r)
r(81.92) = 60+ 0.2(81.92) = 76.384
t = 8 minutes?
Q(8) = 250(0.8)^8 = 41.94304
Q = 41.94304
Heart rate (r)
r(41.94304) = 60+ 0.2(41.94304) = 68.389
t = 10 minutes
Q(10) = 250(0.8)^10 = 26.8435456
Q = 26.8435456
Heart rate (r)
r(26.8435456) = 60+ 0.2(26.8435456) = 65.369
t = 13 minutes
Q(13) = 250(0.8)^13 = 13.7438953472
Q = 13.7438953472
Heart rate (r)
r(13.7438953472) = 60+ 0.2(13.7438953472) = 62.749