Helppppp question 21,22

The general solution of 2 y ln(x)y' = (y^2 + 4)/x is

Sav [38]

Replace $y'$ with $\dfrac{\mathrm dy}{\mathrm dx}$ to see that this ODE is separable:

$2y\ln x\dfrac{\mathrm dy}{\mathrm dx}=\dfrac{y^2+4}x\implies\dfrac{2y}{y^2+4}\,\mathrm dy=\dfrac{\mathrm dx}{x\ln x}$

Integrate both sides; on the left, set $u=y^2+4$ so that $\mathrm du=2y\,\mathrm dy$ ; on the right, set $v=\ln x$ so that $\mathrm dv=\dfrac{\mathrm dx}x$ . Then

$\displaystyle\int\frac{2y}{y^2+4}\,\mathrm dy=\int\dfrac{\mathrm dx}{x\ln x}\iff\int\frac{\mathrm du}u=\int\dfrac{\mathrm dv}v$

$\implies\ln|u|=\ln|v|+C$

$\implies\ln(y^2+4)=\ln|\ln x|+C$

$\implies y^2+4=e^{\ln|\ln x|+C}$

$\implies y^2=C|\ln x|-4$

$\implies y=\pm\sqrt{C|\ln x|-4}$

4 0

3 years ago

What are the total amount of choices possible if an individual is to create a 4 digit password using the digits 0 through 9 incl

qwelly [4]

9000 ways to create 4-digit passwords using digits from 0 to 9 that the first character can't be 0, but not using the digit 0 as the first character.

We have to see how many different 4-digit passwords we can create by using digits from 0 to 9, such that the first character can't be 0.

<h3>What is the combination?</h3>

Each of the different groups or selections can be formed by taking some or all of a number of objects, irrespective of their arrangments is called a combination.

Here we have 4 selections.

Now let's find the number of options for each of these:

First character = 9 options {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

Second character = 10 options {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

Third character = 10 options {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

Fourth character = 10 options {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

The total number of different combinations is just the product of these 4 numbers:

C = 9×10×10×10 = 9,000

So, we can conclude that the correct option is D.

If you want to learn more about combinations visit here;

brainly.com/question/2280026

4 0

2 years ago

Read 2 more answers

The residents of a city voted on whether to raise property taxes. The ratio of yes votes to no votes was 5 to 4 . If there were

Kamila [148]

If there were 5 yes votes for every 4 no votes, there were 5 yes votes for every 9 total votes, so 5/9 of the 7911 votes were yes. 5/9*7911=4395.

7 0

3 years ago

a factory makes 718 toy trains in one day .the toy trains are placed in boxes of 30 in what place will the first digit of the qu

ycow [4]

The first digit of the quotient is the first number of the answer of your division problem. the answer is 2

6 0

3 years ago

When comparing the functions using the equation, which conclusion can be made?

ankoles [38]

Answer:

domain of f(x) is x ≤ 0; domain of f^-1(x) is x ≥ 4

Step-by-step explanation:

The square root function will always give a positive value, so the opposite of the square root function will give non-≤positive values. That means ...

the domain of f(x) is restricted to non-positive values
the domain of the inverse function is restricted to values of x that make the root be of a non-negative number: x ≥ 4

The domain of f(x) is x ≤ 0; the domain of f^-1(x) is x ≥ 4.

8 0

3 years ago