Question 1148464
A scientist begins with 100 milligrams of a radioactive substance that decays exponentially via the function f(x)=a×b^x.
After 2 hours, 70 milligrams of the substance remains.
1. Find a?
a = initial amt, 100 mg
:
2. Find b?
x = 2 hrs, f(x) = 70
{{{100*b^2 = 70}}}
b^2 = {{{70/100}}}
b = {{{sqrt(.7)}}}
b = .867
4. How many milligrams will remain after 13 hours?
{{{f(x) = 100 * .867^13}}}
f(x) = 15.64 mg after 13 hrs