Questions: A person is given an injection of 700 milligrams of penicillin at time t=0. Let f(t) be the amount (in milligrams) of penicillin present in the person's bloodstream t hours after the injection. Then, the amount of penicillin decays exponentially, and a typical formula is f(t)=700 e^(-0.8 t). Complete parts (a) through (c) below.
(a) Give the differential equation satisfied by f(t).
f'(t)=
Transcript text: A person is given an injection of 700 milligrams of penicillin at time $t=0$. Let $f(t)$ be the amount (in milligrams) of penicillin present in the person's bloodstream thours after the injection. Then, the amount of penicillin decays exponentially, and a typical formula is $\mathrm{f}(\mathrm{t})=700 e^{-0.8 t}$. Complete parts $(\mathrm{a})$ through ( c ) below.
(a) Give the differential equation satisfied by $f(t)$.
\[
f^{\prime}(t)=\square
\]
Solution
Solution Steps
Step 1: Define the Function
The amount of penicillin present in the person's bloodstream at time \( t \) is given by the function:
\[
f(t) = 700 e^{-0.8 t}
\]
Step 2: Differentiate the Function
To find the rate of change of the amount of penicillin over time, we differentiate \( f(t) \) with respect to \( t \):
\[
f'(t) = \frac{d}{dt}(700 e^{-0.8 t}) = -560 e^{-0.8 t}
\]
Step 3: Write the Differential Equation
The differential equation that describes the rate of change of the amount of penicillin in the bloodstream is:
\[
f'(t) = -560 e^{-0.8 t}
\]
Final Answer
The differential equation satisfied by \( f(t) \) is:
\[
\boxed{f'(t) = -560 e^{-0.8 t}}
\]