Answer:
Differential equation
Solution
Value of constant k=0.327 days^(-1)
The rumor reaches 80% at 8.48 days.
Step-by-step explanation:
We know
y(t): proportion of people that heard the rumor
y'(t)=ky(1-y), rate of spread of the rumor
Differential equation
Solving the differential equation
Initial conditions:
Value of constant k=0.327 days^(-1)
At what time the rumor reaches 80%?
The rumor reaches 80% at 8.48 days.
Answer:
a) see the plots below
b) f(x) is exponential; g(x) is linear (see below for explanation)
c) the function values are never equal
Step-by-step explanation:
a) a graph of the two function values is attached
__
b) Adjacent values of f(x) have a common ratio of 3, so f(x) is exponential (with a base of 3). Adjacent values of g(x) have a common difference of 2, so g(x) is linear (with a slope of 2).
__
c) At x ≥ 1, the slope of f(x) is greater than the slope of g(x), and the value of f(x) is greater than the value of g(x), so the curves can never cross for x > 1. Similarly, for x ≤ 0, the slope of f(x) is less than the slope of g(x). Once again, f(0) is greater than g(0), so the curves can never cross.
In the region between x=0 and x=1, f(x) remains greater than g(x). The smallest difference is about 0.73, near x = 0.545, where the slopes of the two functions are equal.
