Answer:
- <u>Question 1:</u>
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- <u>Question 2:</u>
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- <u>Question 3:</u>
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- <u>Question 4:</u>
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Explanation:
<u>Question 1: Write down the differential equation the mass of the bacteria, m, satisfies: m′= .2m</u>
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a) By definition: 
b) Given: 
c) By substitution: 
<u>Question 2: Find the general solution of this equation. Use A as a constant of integration.</u>
a) <u>Separate variables</u>

b)<u> Integrate</u>


c) <u>Antilogarithm</u>



<u>Question 3. Which particular solution matches the additional information?</u>
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Use the measured rate of 4 grams per hour after 3 hours

First, find the mass at t = 3 hours

Now substitute in the general solution of the differential equation, to find A:

Round A to 1 significant figure:
<u>Particular solution:</u>

<u>Question 4. What was the mass of the bacteria at time =0?</u>
Substitute t = 0 in the equation of the particular solution:

Answer:
157
Step-by-step explanation:
You don't need to do any multiplication here. It is a fundamental addition problem.
It is given that Lori has got 91 apples and Jay has got 68 of them. We have to find how many apples do they have together.
The correct solution is to add the numbers together:
91+68=157 apples
0.86= 86/100 this is because the 6 is in the hundredths place so the denominator is going to be 100<span />
By the chain rule,

which follows from
.
is then a function of
; denote this function by
. Then by the product rule,
![\dfrac{\mathrm d^2y}{\mathrm dx^2}=\dfrac{\mathrm d}{\mathrm dx}\left[\dfrac1x\dfrac{\mathrm dy}{\mathrm dt}\right]=-\dfrac1{x^2}\dfrac{\mathrm dy}{\mathrm dt}+\dfrac1x\dfrac{\mathrm df}{\mathrm dx}](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Cmathrm%20d%5E2y%7D%7B%5Cmathrm%20dx%5E2%7D%3D%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dx%7D%5Cleft%5B%5Cdfrac1x%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dt%7D%5Cright%5D%3D-%5Cdfrac1%7Bx%5E2%7D%5Cdfrac%7B%5Cmathrm%20dy%7D%7B%5Cmathrm%20dt%7D%2B%5Cdfrac1x%5Cdfrac%7B%5Cmathrm%20df%7D%7B%5Cmathrm%20dx%7D)
and by the chain rule,

so that

Then the ODE in terms of
is

The characteristic equation

has two roots at
and
, so the characteristic solution is

Solving in terms of
gives
