The concentration [tex]C(t)[/tex] of a certain drug in the bloodstream after [tex]t[/tex] minutes is given by the formula [tex]C(t)=0.07\left(1-e^{-0.2 t}\right)[/tex]. What is the concentration after 2 minutes? Round to three decimal places.



Answer :

To determine the concentration of the drug in the bloodstream after 2 minutes, we need to use the given formula for [tex]\( C(t) \)[/tex]. The formula is:

[tex]\[ C(t) = 0.07 \left(1 - e^{-0.2 t} \right) \][/tex]

Here's the step-by-step solution:

1. Substitute [tex]\( t = 2 \)[/tex] into the formula [tex]\( C(t) \)[/tex]:

[tex]\[ C(2) = 0.07 \left(1 - e^{-0.2 \cdot 2} \right) \][/tex]

2. Simplify the exponent:

[tex]\[ C(2) = 0.07 \left(1 - e^{-0.4} \right) \][/tex]

3. Calculate the value of the exponential term [tex]\( e^{-0.4} \)[/tex]:

Using a calculator or a software tool, we find:

[tex]\[ e^{-0.4} \approx 0.670320046 \][/tex]

4. Substitute the value of [tex]\( e^{-0.4} \)[/tex] back into the formula:

[tex]\[ C(2) = 0.07 \left(1 - 0.670320046 \right) \][/tex]

5. Subtract inside the parentheses:

[tex]\[ 1 - 0.670320046 \approx 0.329679954 \][/tex]

6. Multiply by 0.07:

[tex]\[ C(2) = 0.07 \times 0.329679954 \][/tex]

[tex]\[ C(2) \approx 0.02307759678 \][/tex]

7. Round the result to three decimal places:

[tex]\[ C(2) \approx 0.023 \][/tex]

Therefore, the concentration of the drug in the bloodstream after 2 minutes, rounded to three decimal places, is [tex]\( 0.023 \)[/tex].

This detailed step-by-step calculation shows that the concentration after 2 minutes is approximately [tex]\( \boxed{0.023} \)[/tex].