Which of the following represent an exponential growth function?

Step-by-step explanation:

Exponential Growth Function

The exponential function is often used to model natural growing or decaying processes, where the change is proportional to the actual quantity.

An exponential growth function is expressed as:

Where:

C(t) is the actual value of the function at time t

Co is the initial value of C at t=0

r is the (positive) growth rate, expressed in decimal

Since r is positive, 1+r is greater than 1.

From the available options, only the last two of them correspond to exponential functions according to the definition above.

Note the third option has a base of 1/3 which is not greater than 1. In fact, it corresponds to an exponential decay function.

The last option has a base 3 and corresponds to a value of r=2 which correctly fits with the definition presented above, thus the correct choice is

B) -3/2

Step-by-step explanation:

If [x/2]=0 then x/2 is a number such that the least integer greater than or equal to x/2 is 0. We can rewrite this as the inequality x/2≤0. Then, the value of x in C, D and E is wrong because they are positive numbers, then x/2 would be a positive number which contradicts this inequality.

Now, 0 is the least integer that satisfies this inequality, therefore we cannot have that x/2≤-1 since -1 is an integer and -1<0. Then x/2>-1. This discards A as wrong, because for x=-2, x/2=-1, contrary to x/2>-1.

Thus B is the right answer. To verify, if x=-3/2, then x/2=-3/4 and we have that -1<-3/4≤0 as required.