Help help math please please

1. The given equation is probably supposed to read

y'' - 2y' - 3y = 64x exp(-x)

First consider the homogeneous equation,

y'' - 2y' - 3y = 0

which has characteristic equation

r² - 2r - 3 = (r - 3) (r + 1) = 0

with roots r = 3 and r = -1. Then the characteristic solution is

[tex]y = C_1 e^{3x} + C_2 e^{-x}[/tex]

and we let y₁ = exp(3x) and y₂ = exp(-x), our fundamental solutions.

Now we use variation of parameters, which gives a particular solution of the form

[tex]y_p = u_1y_1 + u_2y_2[/tex]

where

[tex]\displaystyle u_1 = -\int \frac{64xe^{-x}y_2}{W(y_1,y_2)} \, dx[/tex]

[tex]\displaystyle u_2 = \int \frac{64xe^{-x}y_1}{W(y_1,y_2)} \, dx[/tex]

and W(y₁, y₂) is the Wronskian determinant of the two fundamental solutions. This is

[tex]W(y_1,y_2) = \begin{vmatrix}e^{3x} & e^{-x} \\ (e^{3x})' & (e^{-x})'\end{vmatrix} = \begin{vmatrix}e^{3x} & e^{-x} \\ 3e^{3x} & -e^{-x}\end{vmatrix} = -e^{2x} - 3e^{2x} = -4e^{2x}[/tex]

Then we find

[tex]\displaystyle u_1 = -\int \frac{64xe^{-x} \cdot e^{-x}}{-4e^{2x}} \, dx = 16 \int xe^{-4x} \, dx = -(4x + 1) e^{-4x}[/tex]

[tex]\displaystyle u_2 = \int \frac{64xe^{-x} \cdot e^{3x}}{-4e^{2x}} \, dx = -16 \int x \, dx = -8x^2[/tex]

so it follows that the particular solution is

[tex]y_p = -(4x+1)e^{-4x} \cdot e^{3x} - 8x^2\cdot e^{-x} = -(8x^2+4x+1)e^{-x}[/tex]

and so the general solution is

[tex]\boxed{y(x) = C_1 e^{3x} + C_2e^{-x} - (8x^2+4x+1) e^{-x}}[/tex]

2. I'll again assume there's typo in the equation, and that it should read

y''' - 6y'' + 11y' - 6y = 2x exp(-x)

Again, we consider the homogeneous equation,

y''' - 6y'' + 11y' - 6y = 0

and observe that the characteristic polynomial,

r³ - 6r² + 11r - 6

has coefficients that sum to 1 - 6 + 11 - 6 = 0, which immediately tells us that r = 1 is a root. Polynomial division and subsequent factoring yields

r³ - 6r² + 11r - 6 = (r - 1) (r² - 5r + 6) = (r - 1) (r - 2) (r - 3)

and from this we see the characteristic solution is

[tex]y_c = C_1 e^x + C_2 e^{2x} + C_3 e^{3x}[/tex]

For the particular solution, I'll use undetermined coefficients. We look for a solution of the form

[tex]y_p = (ax+b)e^{-x}[/tex]

whose first three derivatives are

[tex]{y_p}' = ae^{-x} - (ax+b)e^{-x} = (-ax+a-b)e^{-x}[/tex]

[tex]{y_p}'' = -ae^{-x} - (-ax+a-b)e^{-x} = (ax-2a+b)e^{-x}[/tex]

[tex]{y_p}''' = ae^{-x} - (ax-2a+b)e^{-x} = (-ax+3a-b)e^{-x}[/tex]

Substituting these into the equation gives

[tex](-ax+3a-b)e^{-x} - 6(ax-2a+b)e^{-x} + 11(-ax+a-b)e^{-x} - 6(ax+b)e^{-x} = 2xe^{-x}[/tex]

[tex](-ax+3a-b) - 6(ax-2a+b) + 11(-ax+a-b) - 6(ax+b) = 2x[/tex]

[tex]-24ax+26a-24b = 2x[/tex]

It follows that -24a = 2 and 26a - 24b = 0, so that a = -1/12 = -12/144 and b = -13/144, so the particular solution is

[tex]y_p = -\dfrac{12x+13}{144}e^{-x}[/tex]

and the general solution is

[tex]\boxed{y = C_1 e^x + C_2 e^{2x} + C_3 e^{3x} - \dfrac{12x+13}{144} e^{-x}}[/tex]

Answer:

509.6 calories

Step-by-step explanation:

196+196=392 calories

10g of bacon=19.6 calories

60g of bacon=19.6×6=117.6 calories

392+117.6=509.6 calories

Answer:

x=11/5

Step-by-step explanation:

isolate x

22/10 = 10x/10

22/10 = x

simplify

11/5 = x

Answer:

60

Step-by-step explanation:

1 dozen=12 eggs. 12 ×5=60

Answer:

60

Step-by-step explanation:

dozen=12

5x12=60

Answer:

PLEASE MARK ME AS BRANLIEST!!!!!

Step-by-step explanation:

a1 = first term; an= an-1 + d a1 = the first term in the sequence an = the nth term in the sequence an-1 = the term before the nth term n = the term number d = the common difference.

{10, 15, 20, 25, 30, 35, } first term = 10, common difference = 5 recursive formula: a1= 10; an= an-1 + 5

f(n) = f(n-1) + 12

f(1) = 7

f(2) = (7-1) + 12 = 18

f(3) = (18-1) + 12 = 29

f(4) = (29-1) + 12 = 40

f(5) = (40-1) + 12 = 51

7, 18, 29, 40, 51

[tex](-x) \cos(-x)\\\\=-x \cos x \\\\=-(x \cos x)\\\\=-2[/tex]

Answer:

300°

Step-by-step explanation:

what is 5/6 of a full rotation?

A full rotation is 360°

360 * 5/6 = 300°

Answer:

40 students earned a B on this paper.

40%×80=32 people who chose action as their fav.

Answer:

240oz.

Step-by-step explanation:

15oz=1batch

She needs 16 batches.

15oz. x 16batches = 240oz.

Hope this helps :)

Answer:

k=2.117

Step-by-step explanation:

Answer:

3.017 + k = 5.134

So, k = 5.134 - 3.017

So, k = 2.117

Answer:

319973/400

Step-by-step explanation:

800 - 27/4%

800 - ( 27/4 × 1/100)

800 - 27/400

= 319973/400

Answer:

This is indeed a function

Answer:

y = (x - 1)(x - 3)

y = (x + 2)^2

Step-by-step explanation:

3)

Has roots at x = {1, 3}

y = (x - 1)(x - 3)

4)

Has double root at x = -2

y = (x + 2)^2

Answer:

[tex]\huge\boxed{C)\ -\dfrac{1}{5}}[/tex]

Step-by-step explanation:

The reciprocal of 5: [tex]\dfrac{1}{5}[/tex]

The negative reciprocal of 5: [tex]-\dfrac{1}{5}[/tex]

Answer:

B. because it just isssssssss I'm typing things to let me answerrr

Answer:

4(2x raise to power 2-4-7x)

Answer:

A: the area of the walls that are being painted

C: the cost per gallon of different paints

F: the number of square feet that can be painted per gallon of paint

Step-by-step explanation:

Answer:

the set of side lengths will be d

[tex]~~~~~~\textit{vertical parabola vertex form} \\\\ y=a(x- h)^2+ k\qquad \begin{cases} \stackrel{vertex}{(h,k)}\\\\ \stackrel{"a"~is~negative}{o pens~\cap}\qquad \stackrel{"a"~is~positive}{o pens~\cup} \end{cases} \\\\[-0.35em] \rule{34em}{0.25pt}[/tex]

[tex]\begin{cases} h= 0\\ k = 4 \end{cases}\implies y=a(x-0)^2+4~\hfill \textit{we also know that} \begin{cases} x = 1\\ y = 3 \end{cases} \\\\\\ 3=a(1-0)^2+4\implies 3=1a+4\implies \boxed{-1=a} \\\\\\ y=-1(x-0)^2+4\implies \blacktriangleright y = -x^2+4\blacktriangleleft[/tex]

Answer:

A.    y = –(x – 1)2 + 3    = Rewrite in vertex form and use this form to find the vertex  (h,k).    (1,3)=  Already in vertex form.  y=−(x−1)2+3

OR

D.    y = –x^2 + 4    = Rewrite in vertex form and use this form to find the vertex  (h,k).    (0,4)=  Find the vertex form.     y=−(x+0)2+4

Step-by-step explanation:

A.    y = –(x – 1)2 + 3    = Rewrite in vertex form and use this form to find the vertex  (h,k).    (1,3)=  Already in vertex form.  y=−(x−1)2+3

B.    y = –x^2 – 4    = Rewrite in vertex form and use this form to find the vertex  (h,k).    (0,−4)=   Find the vertex form.     y=−(x+0)2−4

C.    y = –x^2 + 3     = Rewrite in vertex form and use this form to find the vertex  (h,k).    (0,3)=  Find the vertex form.     y=−(x+0)2+3

D.    y = –x^2 + 4    = Rewrite in vertex form and use this form to find the vertex  (h,k).    (0,4)=  Find the vertex form.     y=−(x+0)2+4

Answer:

13.77777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777777

Answer:

f(x)=290+30x

Step-by-step explanation:

the 290 is for the money initially put in, the 30 is for the thirty dollars, and the x represents the number of weeks.

Answer:

Use the distributive property to multiply 2 by x−1.

l2x-2I=11

2x-2=-11

Add 2 to both sides of the equation.

2x=-9

Divide both sides by 2.

x=13/2

That's the final answer

Hope u have a great day!!

Answer:

Mean = 8

Variance = 22

Standard deviation = 4.6904

Step-by-step explanation:

To find out Mean the formula is : total sum of data set / number of values

(11 + 11 + 3 + 1 + 11 + 11) / 6 = 48 / 6 = 8

Mean = 8

Now for variance we will form a table

x                  11     11     3      1      11      11

(x - Mean)    3     3    -5     -7      3      3  

(x - Mean)²   9     9    25    49    9      9

Now we the formula of variance =

Variance = (9+9+25+49+9+9)/(6-1) = 110/5 = 22

Variance = 22

Now we know Standard deviation = √(variance)

Therefore standard deviation = √22 = 4.6904

Hope this helps!<3

Answer: Mean = 8

Step-by-step explanation:

Answer:

Weight On the Moon: 41.34 kilograms

Step-by-step explanation:

Step-by-step explanation:

4b + z I think lol I honestly looked it up

Answer:

the answer is slope=94, y-intercept = 2

Step-by-step explanation:

i took the test

Answer:

Area solution

Step-by-step explanation:

A=(16+10)×12/2= 156 m^2

Answer:

c po is the correct aswer

Step-by-step explanation:

correct me if im wrong hope it's help

thanks

Answer:

B. Insurance ensures that losses are not passed on to society

Hope this helps :)

Answer:

m=1

Step-by-step explanation:

[tex]m=\frac{8-6}{2-0} =\frac{2}{2} =1[/tex]

I hope this help you