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A biologist observed a population of bacteria that grew at a rate expressed by the exponential equation
f(t) = 256e0.06111)
where t is in minutes. How long will it take the population to reach 5 times its initial value?
Round to two decimal places and do not include "t =" in your answer.

Respuesta :

Answer:

It will take 26.34 minutes for the population to reach 5 times its initial value

Step-by-step explanation:

Exponential Growing

The population of bacteria grows at a rate expressed by the equation:

[tex]f(t)=256e^{0.06111t}[/tex]

Where t is in minutes.

We need to know when the population will reach 5 times its initial value. The initial value can be determined by setting t=0:

[tex]f(0)=256e^{0.06111\cdot 0}=256\cdot 1=256[/tex]

Now we find the time when the population is 5*256=1,280. The equation to solve is:

[tex]1,280=256e^{0.06111t}[/tex]

Dividing by 256:

[tex]e^{0.06111t}=1,280/256=5[/tex]

Taking natural logarithms:

[tex]ln\left(e^{0.06111t}\right)=ln5[/tex]

Applying the logarithm properties:

[tex]0.06111t=ln5[/tex]

Solving for t:

[tex]t=ln5/0.06111=26.34[/tex]

It will take 26.34 minutes for the population to reach 5 times its initial value