Answer
$80~beats~per~second$
Work Step by Step
The pulse of the patient is the frequency of the given function. The frequency is the inverse of the period. According to item (b) the period is 0.75 seconds:
$f=\frac{1}{0.75}=\frac{4}{3}~beats~per~second=\frac{4}{3}\times60=80~beats~per~second$
