Question

The amount of a radioactive isotope decays in half every year. The amount of the isotope can be modeled by f(x) = 346(1/2)^x and f(1) = 173. What does the 1 represent?

Answer 1

A. The starting amount of the isotope
B. The amount of the isotope after one year
C. The rate the isotope decreases
D. The number of years that have passed

Answer 2

x = number of years that have passed
x is the input of the function

f(x) is the output and represents the amount of material left over (after x years have gone by). Often y = f(x) so you can replace f(x) with y if you want.

The benefit of keeping the f(x) notation is that you can see both the input and output at the same time for the same equation

for example, if you claim that f(3) = 10 then that means x = 3 years have passed by and y = 10 is the amount of material left over.

Answer 3

@jim_thompson5910 when they ask what one represents are they talking about 1/2?

Answer 4

`f(1) = 173. What does the 1 represent?`

they're referring to the `1` in `f(1)`

Answer 5

would it be the amount after one year? @jim_thompson5910

Answer 6

f(1) all together represents the amount left over after one year. This is the y value

but they want the x value

Answer 7

arent they asking what 1 represents?

Answer 8

so it would be amount left over after one year?