First make x the subject:-
3x = F(x) + 4
x = (F(x) + 4) / 3
f(-1(x) = (x + 4) / 3 answer
Answer: Our Cost function is discontinuous at every integer after x>10.
Step-by-step explanation:
Since we have given that
For the first 10 minutes , the service charges = $0.30
Let the number of additional minute be 't'.
Amount charge for each additional minute = $0.05
Using the greatest integer function:
So, Cost C of a call in terms of time 't' minutes would be

As we know that Greatest integer is discontinuous at every integer.
So, our Cost function is discontinuous at every integer after x>10.
Answer:
In mathematics, exponential decay describes the process of reducing an amount by a consistent percentage rate over a period of time. It can be expressed by the formula y=a(1-b)x wherein y is the final amount, a is the original amount, b is the decay factor, and x is the amount of time that has passed.
Step-by-step explanation: