Question

If a bacteria population starts with 100 bacteria and doubles every three hours, then the number of bacteria after t hours is n = f(t) = 100 · 2^t/3. Find the inverse of this function and explain its meaning.

Answer 1

Answer:

$f^{-1}=3ln_2(\frac{t}{100})$

f^-1 represents the number of hours the bacteria developed

Step-by-step explanation:

$f(t) = 100 \cdot 2^\frac{t}{3}$

To find inverse of a function , replace f(t) with y

$y= 100 \cdot 2^\frac{t}{3}$

replace t with y and y with x

$x= 100 \cdot 2^\frac{y}{3}$

solve for y

divide both sides by 100

$\frac{x}{100} =2^\frac{y}{3}$

take ln on both sides

$ln \frac{x}{100} =\frac{y}{3}ln 2$

divide both sides by ln

$ln_2(\frac{x}{100}) =\frac{y}{3}$

multiply by 3 on both sides

$y=3ln_2(\frac{x}{100})$

Replace x with t  and y with f^-1

$f^{-1}=3ln_2(\frac{t}{100})$

f^-1 represents the number of hours the bacteria developed