- #1

lionely

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## Homework Statement

Patients with certain heart problems are often treated with digitoxin, a derivative of the digitalis plant. The rate at which a person's body eliminates digitoxin is proportional to the amount present. In 1 day, about 10% of any given amount of the drug will be eliminated. Suppose that a "maintenance dose" of 0.05mg is given daily to a patient. Estimate the total amount of digitoxin that should be present in the patient after several months.

## Homework Equations

## The Attempt at a Solution

My teacher says there is no answer and that there is a problem with the question. But I don't agree!

Several months compared to 1 day is a lot of time, so I believe the answer is the sum to infinity ,

where

the common ratio r, = 0.90 and a =.05

Also when I write out the terms I noticed that each term is equivalent to the GP sum formula.

Meaning T2 = Sum of first two terms of the sequence if it was a GP.

So I believe T∞ = S∞

S∞ = a/(1-r) = .05/(1-.90 ) = .50mg