From the statement, we know that Miss Butterkey's heart rate is 80 beats per minute.
So the ratio of beats per minute is:
The number of beats as a function of time is given by the product:
Where t is the time in minutes.
(0) If we define:
• M = # of minutes,
,• b = # of beats after M minutes.
Using the equation of b(t), we have:
(1) Domain and range
If we consider the independent variable as the number of minutes M, the domain is:
If we consider the dependent variable as the number of beats b, the range is:
(2) # of beats after half an hour
After half an hour the time is t = 30 min. Replacing this value in the equation of b(t), we get:
(3) The graph of heartbeats as a function of the minutes is discrete. That's because we can only have an integer number of beats.
(4) Labels of the graph
• horizontal label: number of minutes M,
,• vertical label: number of beats b.
(5) Graph
Answers
• (0), M(b) = b/80
,• (1) ,Domain = 0, 1, 2, 3, ... , Range = 0, 80, 160, 240, ...
,• (2), b(30 min) = 2400 beats
,• (3), The graph is discrete.
,• (4) ,Horizontal label: # of minutes M, Vertical label: # of beats
,• (5), Graph
