The amount of a radioactive material changes with time. The table below shows the amount of radioactive material f(t) left after time t:

t(hours) 0 1 2
f(t) 180 90 45

Which exponential function best represents the relationship between f(t) and t?
f(t) = 0.5(180)^t
f(t) = 180(0.25)^t
f(t) = 180(0.5)^t
f(t) = 0.5(50)^t

Question

The amount of a radioactive material changes with time. The table below shows the amount of radioactive material f(t) left after time t:


t(hours)	0	1	2
f(t)	180	90	45


Which exponential function best represents the relationship between f(t) and t?
 f(t) = 0.5(180)^t
 f(t) = 180(0.25)^t
 f(t) = 180(0.5)^t
 f(t) = 0.5(50)^t

anonymous · Answer

I know it has to be either B or C.

agl202 · Answer

90 is half of 180, and 45 is half of 90... so it looks like you have 180 (.5)^t
f(t) = 180(0.5)^t

Hope this helps! : )

anonymous · Answer

Thanks!

agl202 · Answer

Ur welcome! :)