Answer:
The radius is 9 cm.
Step-by-step explanation:
The formula for calculating the circumference of a circle is
Where r is the radius and C is the circumference.
It was given in the question that; the circumference, .
We substitute this into the formula to obtain;
Divide both sides by
The radius is 9cm
Option A is correct.
If we evaluate the function at , i.e. at the beginning, we have
with each minute, you multiply the current number of cell by 2, so they double every minute.
Option B is incorrect, because if the number of cells increases by 2 every minute, the function would be
Option C is incorrect, because after one minute (i.e. when x=1) we have
cells, so 75 is not the number of cells after one minute
Option D is incorrect in both the initial value and the behaviour of the function