Question

Use the rule of 70 to estimate the time it will take an initial quantity to drop to half its value when:

P= 4.61(0.999)^t,

where t is in years. Round your answer to two decimal places.

The half-life is approximately______ years.

Answer 1

The initial quantity is 4.61 so half of that is 2.255
so we need to solve this:
2.255=4.61(.999)^t

Answer 2

using logs?

Answer 3

yes

Answer 4

hmmmmm...yeah about that heheh

Answer 5

t= log(1/2)/log (0.999) right?