Notice that y=0 will not give you an answer, because this is an exponential function.
A
a
5 000 000 bytes
B
b
After about 12.29 minutes
C
c
After about 22.25 minutes
Practice makes perfect
a
We have been given an equation that describes the spread of the virus. Examining the equation, we see that it is an exponential function of the form y=ab^x, where a is the initial value and b is the multiplier. We can identify these variables directly.
y&= 5 000 000( 1/2)^t
a&= 5 000 000
b&= 1/2
As we can see, the initial value is 5 000 000. This is the initial number of bytes of information on Deniz's hard drive.
b
By setting y equal to 1000, we can determine the number of minutes it will take, t, for the number of bytes to equal this amount.
After about 12.29 minutes there are 1000 bytes of information left.
c
The hard drive will be completely erased when there are 0 files left. However, we are dealing with an exponential function, which means the model will only approach 0. This means we cannot solve y=0. To approximate the number of minutes it will take, we can instead solve the inequality y<1.
