A Cepheid variable star is a star whose brightness alternately increases and decreases. Suppose that Cephei Joe is a star for which the interval between times of maximum brightness is 5.3 days. Its average brightness is 2.9 and the brightness changes by /- 0.35. Using this data, we can construct a mathematical model for the brightness of Cephei Joe at time t, where t is measured in days:______.B(t)=4.2 +0.45sin(2pit/4.4)
(a) Find the rate of change of the brightness after t days.
(b) Find the rate of increase after one day.

Answer:

A) 7 and 8

Step-by-step explanation:

root of 7 is 2.64575..... then when u multiply by 3

3*2.64575=7.93725

Answer:

12m by 3m

Step-by-step explanation:

lol please mark brainliest

Answer:

45 Degrees

Step-by-step explanation:

Compare to its other side

Answer:

8 Hours.

Step-by-step explanation:

Answer:

The probability that the device fails during its first hour of operation is 0.625.

Step-by-step explanation:

The joint density function of the lifetimes of the two components, both measured in hours, is:

[tex]f(x,y)=\frac{x+y}{8};\ 0<x<2,\ 0<y<2[/tex]

Compute the probability that the device fails during its first hour of operation as follows:

[tex]P[(X<1)\cup (Y<1)]=1-\int\limits^{2}_{1} {\int\limits^{2}_{1} {\frac{x+y}{8}} \, dx } \, dy[/tex]

                                  [tex]=1-\int\limits^{2}_{1} {\frac{x^{2}+2xy}{16}}|^{2}_{1} \, dy\\\\=1- \int\limits^{2}_{1}[{\frac{4+4y}{16}-\frac{1+2y}{16}}] \, dy\\\\=1-\int\limits^{2}_{1}{\frac{3+2y}{16}}\, dy\\\\=1-[\frac{3y+y^{2}}{16}]^{2}_{1}\\\\=1-0.375\\\\=0.625[/tex]

Thus, the probability that the device fails during its first hour of operation is 0.625.

Step-by-step explanation:

Inverse of p matrix is in picture

i wish it will make u easy to do♥️✌️

Answer:

no puedo alludar te perdón

Answer:

0.49 49

=

49      this is a fraction

99

Step-by-step explanation:

Let

XXX

x

=

0.49

¯¯¯¯

49

then

XXX

100

x

=

49.49

¯¯¯¯

49

and

XXX

99

x

=

100

x

−

x

=

49

XXX

x

=

49

99

Answer: x=60

Step-by-step explanation:

x+22+x+6+x−28=180

Step 1: Simplify both sides of the equation.

x+22+x+6+x−28=180

x+22+x+6+x+−28=180

(x+x+x)+(22+6+−28)=180(Combine Like Terms)  22+6=28 and then 28-28=0

3x=180  

3x=180

Step 2: Divide both sides by 3.

3x/3 = 180/3

x=60

hope this was helpful.

Answer: The answer would be -5w-1

Step-by-step explanation:

Answer:

xcgvb                     vgjbnnnnnnnnnn vbjn bvh

Step-by-step explanation:

Answer:

10

Step-by-step explanation:

you do the one plus the nine which gives you 11 then subtract 2 which gets you 9 then add 4 which gets you 13 then minus 3 which gets you 10.

Answer:

$1

Step-by-step explanation:

i hope i read it right

Answer:

1

Step-by-step explanation:

cuz half of 2 is 1

Answer:

-0.24 ; 0.71

Step-by-step explanation:

Given that :

Mean number of siblings (m) = 3.76

Standard deviation (s) = 3.18

Z score associated with 3 siblings

x = 3

Using the relation :

Zscore = (x - m) / s

Zscore = (3 - 3.76) / 3.18

Zscore = - 0.76 / 3.18

Zscore = −0.238993

Zscore = - 0.24

2.) proportion of respondents with more than 2 siblings

Using the z probability calculator :

X > 2

Obtain the standardized score :

Zscore = (x - m) / s

Zscore = (2 - 3.76) / 3.18

Zscore = - 1.76 / 3.18

Zscore = −0.5534591

Zscore = - 0.55

Using the z table :

P(Z ≥ - 0.55) = 1 - p(Z ≤ - 0.55) ; p(Z ≤ - 0.55) = 0.2912

1 - p(Z ≤ - 0.55) = 1 - 0.2912 = 0.7088 = 0.71

Answer:

y = 8º

y = 8º  

Step-by-step explanation:

Given:

(10x - 61)º  

(18y + 5)º

(x + 10)º

Find:

x and y

Computation:

(10x - 61) + (x + 10) = 180

11x - 51 = 180

11x = 231

x = 21º

(10x - 61)º   = (18y + 5)º      [Vertical opposite angle]

10x - 61 = 18y + 5

10x - 18y = 66

5(21) - 9y = 33

y = 8º

Answer:

1,232 ft/min (feet per minute)

Step-by-step explanation:

14 miles = 73,920 feet

1 hour = 60 minutes

73, 920 / 60 = 1,232 feet/minute

Answer:

The density is 8.5 g/cm³

Step-by-step explanation:

The density formula is density = mass/volume

When we plug our numbers into the formula, we get:

Density = 2210 / 260

We can then solve and get our answer 8.5 g/cm³

It is given a piece of metal has a mass of 2210g the volume of the metal is 260cm ^3 . The density is 8.5 g/cm³.

Suppose that a finite amount of substance is there having its properties as:

The mass of substance = m kg

The density of substance = d kg/m³

The volume of that substance = v m³

Then, they are related as:

[tex]d = \dfrac{m}{v}[/tex]

It is given a piece of metal has a mass of 2210g the volume of the metal is 260cm ^3 .

density = mass/volume

When we substitute our numbers into the formula, we get:

Density = 2210 / 260

Density = 8.5 g/cm³

It is given a piece of metal has a mass of 2210g the volume of the metal is 260cm ^3 . The density is 8.5 g/cm³

Learn more about mass, volume and density relation here:

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Answer:

6/53

Step-by-step explanation:

Answer:

$69.21

Step-by-step explanation:

Since the box has a square base the length and breadth of the box will be equal. Let it be [tex]x[/tex]

Let h be the height of the box

V = Volume of the box = [tex]620\ \text{cm}^3[/tex]

[tex]x^2h=620\\\Rightarrow h=\dfrac{620}{x^2}[/tex]

Now surface area of the box with an open top is given

[tex]s=x^2+4xh\\\Rightarrow s=x^2+4x\dfrac{620}{x^2}\\\Rightarrow s=x^2+\dfrac{2480}{x}[/tex]

Differentiating with respect to x we get

[tex]\dfrac{ds}{dx}=2x-\dfrac{2480}{x^2}[/tex]

Equating with zero

[tex]0=2x-\dfrac{2480}{x^2}\\\Rightarrow 2x^3-2480=0\\\Rightarrow x^3=\dfrac{2480}{2}\\\Rightarrow x=(1240)^{\dfrac{1}{3}}\\\Rightarrow x=10.74[/tex]

Double derivative of the function

[tex]\dfrac{d^2s}{ds^2}=2+\dfrac{4960}{x^3}=2+\dfrac{4960}{1240}\\\Rightarrow \dfrac{d^2s}{ds^2}=6>0[/tex]

So, x at 10.74 is the minimum value of the function.

[tex]h=\dfrac{620}{x^2}\\\Rightarrow h=\dfrac{620}{10.74^2}\\\Rightarrow h=5.37[/tex]

So, minimum length and breadth of the box is 10.74 cm while the height of the box is 5.37 cm.

The total area of the sides is [tex]4xh=4\times 10.74\times 5.37=230.7\ \text{cm}^2[/tex]

The area of the base is [tex]x^2=10.74^2=115.35\ \text{cm}^2[/tex]

Cost of the base is $0.40 per square cm

Cost of the side is  $0.10 per square cm

Minimum cost would be

[tex]230.7\times 0.1+0.4\times 115.34=\$69.21[/tex]

The minimum cost of the box is 69.21 dollars.

Allison's average driving speed in miles per hour is 65.

Speed is the ratio of distance and time.

It shows how fast an object is moving at a given time.

We have,

130 miles = 2 hours

Divide 2 on both sides.

130/2 miles = 1 hour

65 miles = 1 hour

Thus,

The average speed is 65 miles per hour.

Learn more about speed here:

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Since S is closed, you can use the divergence theorem, which says

[tex]\displaystyle\iint_S \vec F(x,y,z) \cdot \mathrm d\vec S=\iiint_R \mathrm{div}\vec F(x,y,z)\,\mathrm dV[/tex]

where R is the interior of the surface S.

We have

div F (x, y, z) = ∂/∂x (0) + ∂/∂y (y) + ∂/∂z (-z) = 1 - 1 = 0

so the flux would be 0.

In this exercise we have to calculate the flux by the divergent theorem:

The flux would be ZERO

Since S is closed, you can use the divergence theorem, which says:

[tex]\int\limits\int\limits_s {F(x,y,z} \, ds= \int\limits \int\limits\int\limits_R {divF(x, y, z)} \, dv[/tex]

where R is the interior of the surface S. We have:

[tex]\nabla F (x, y, z) = 1-1= 0[/tex]

so the flux would be ZERO.

See more about vectorial calculus at : brainly.com/question/6960786

Answer:

The number is 2

Step-by-step explanation:

To attempt this question, we need to represent the number with (x).

Let the number be x

Five more than the number is:

5 + x

Seven-halves means 1/2 × 7 = 7/2

Mathematically, the question is saying:

5 + x = 7/2 × x

5 + x = 7x/2

Cross multiply;

2(5 + x) = 7x

10 + 2x = 7x

We collect like terms;

10 = 7x - 2x

10 = 5x

x = 10/5

x = 2

The number represented by x is 2

We want to convert the given sentence into an equation, and then solve it. We will see that the number is 2.

We start with the sentence:

"Five more than a number is equal to seven-halves of the number"

if we define x as the number, we can write:

5 + x = (7/2)*x

Now we can solve this equation for x, we will get:

5 + x = (7/2)*x

5 = (7/2)*x - x = (7/2 - 1)*x

5 = (7/2 - 2/2)*x = (5/2)*x

(2/5)*5 = x

2 = x

So the number is 2.

If you want to learn more about linear equations, you can read:

https://brainly.com/question/4074386

Answer:

5/7

Step-by-step explanation:

You find a slope by using the equation y2-y1/x2-x1.

In this case: 15-5/21-7

10/14

5/7

Answer:

Being proportional between two entities, refers to the 'Constant of Proportionality' that would be fixed between them which establishes a relationship between them when multiplied or divided.

If we considered it on a graph, the 'Constant Of Proportionality' may take any real values between the coordinate pairs x and y [x,y]. As even 0 is a real number, it will surely be a constant of proportionality when multiplied since its product would result in itself (0). Hence, both x and y turns 0.

As the coordinates of the origin are always (0,0), the graph  (Or the slope) would surely pass through the origin.

Example :

If we consider a graph such that x=y.

And if we multiply or divide any real number (a) between them.

ax=ay

As a is a variable, and can take the value of 0, the graph can pass through the origin as x and y nullify becoming the coordinates of the origin.

Answer:

= -56.22

Step-by-step explanation:

have a great day

pls mark as brainliest!

hope this helped!

Answer:

-56.22

just calculated it (:

Answer:

Unitary cost (per pound)= $0.682

Step-by-step explanation:

Giving the following information:

Total cost= $3.75

Total pounds= 5.5 pounds

To calculate the unitary cost of each pound, we need to use the following formula:

Unitary cost= total cost / total pounds

Unitary cost per pound= 3.75 / 5.5

Unitary cost per pound= $0.682

Answer:

2

Step-by-step explanation:

y=mx+n m is slope

y-6=2(x+3) so y=2x+12  m=2 is slope.

417

Step-by-step explanation:

I hope this helps :)

Answer:

[tex]m=\frac{-14}{11}[/tex]

General Formula and Concepts:

Pre-Algebra

Algebra I

Step-by-step explanation:

Step 1: Define

Point (9, -5)

Point (-2, 9)

Step 2: Find slope m

Answer:

Between 2.25 and 2.5

Step-by-step explanation:

The square root of 6 is 2.4494.... which is closer to 2.5