The decay of 230 mg of an isotope is described by the function A(t)= 230e-0.031t, where t is time in years. Find the amount left after 26 years. Round your answer to the nearest mg. Show all of your work for full credit.

Question

homeworksucks · Answer

Just plug in 26?

anonymous · Answer

for t?

homeworksucks · Answer

yup

anonymous · Answer

what about for e?
is that the natural base?

homeworksucks · Answer

I think so, I think e is just the constant

anonymous · Answer

okay so i plugged it in and got 230e-0.806

anonymous · Answer

actually the problem didn't copy right it should be 230e^-0.806

homeworksucks · Answer

Oh, yeah, still plug it in though

anonymous · Answer

what do i do after that?

homeworksucks · Answer

Find e to the -0.806th power, and times it by 230

anonymous · Answer

And then you party like a rock star

homeworksucks · Answer

Did you get 103 mg?

anonymous · Answer

okay so now i have e=2.71828 
230(2.71828)^-0.806
625.2044^-0.806

anonymous · Answer

how in the world did you get 103....?

anonymous · Answer

@Homeworksucks

homeworksucks · Answer

Oh umm BEDMAS

homeworksucks · Answer

230 (e^-0.806)

anonymous · Answer

e=2.71828

anonymous · Answer

so would it be 2.71828^-0.806?

homeworksucks · Answer

yup, times 230

anonymous · Answer

i'm confused about how you have -0.806 as an exponent though...how would you multiply that out?

homeworksucks · Answer

e^-0.806 is 0.4466410621, times that by 230

anonymous · Answer

how did you figure that out though?

homeworksucks · Answer

It goes exponents then Multiplication, according to BEDMAS(or PEMDAS)

anonymous · Answer

....i've never learned how to multiply an exponent that is negative and a decimal though.  that's what i'm still confused about.  i know how to do pemdas (:

anonymous · Answer

i appreciate your help by the way (: