Eighty-one million four hundred twelve thousand six hundred fifty

A Cepheid variable star is a star whose brightness alternately increases and decreases. For a certain star, the interval between

victus00 [196]

Answer:

a) $\frac{dB}{dt} = \frac{5\pi}{4.2} \cdot \cos \left(2\pi\cdot \frac{t}{4.2} \right)$ , b) $\frac{dB}{dt}\approx 5.595$

Step-by-step explanation:

a) The rate of change of the brightness of the Cepheid can be determined by deriving the function in time:

$\frac{dB}{dt} = \left(\frac{2\pi}{4.2} \right)\cdot 0.25\cdot \cos (2\pi\cdot \frac{t}{4.2})$

$\frac{dB}{dt} = \frac{5\pi}{4.2} \cdot \cos \left(2\pi\cdot \frac{t}{4.2} \right)$

b) The rate of increase after one day is:

$\frac{dB}{dt} = \frac{5\pi}{4.2} \cdot \left(2\pi \cdot \frac{1}{4.2} \right)$

$\frac{dB}{dt}\approx 5.595$

4 0

3 years ago

Please I Really Need Help.The coordinate plane below represents a city. Points A through F are schools in the city.

almond37 [142]

Answer:

Part A) The system of inequalities is

$x\geq2$ and $y\geq2$

Part B) In the procedure

Part C) The schools that Natalie is allowed to attend are A,B and D

Step-by-step explanation:

Part A: Using the graph above, create a system of inequalities that only contain points C and F in the overlapping shaded regions

we have

Points C(2,2), F(3,4)

The system of inequalities could be

$x\geq2$ -----> inequality A

The solution of the inequality A is the shaded area at the right of the solid line x=2

$y\geq2$ -----> inequality B

The solution of the inequality B is the shaded area above of the solid line y=2

see the attached figure N 1

Part B: Explain how to verify that the points C and F are solutions to the system of inequalities created in Part A

we know that

If a ordered pair is a solution of the system of inequalities, then the ordered pair must satisfy both inequalities

Verify point C

C(2,2)

Inequality A

$x\geq2$ -----> $2\geq2$ ----> is true

Inequality B

$y\geq2$ ------> $2\geq2$ ----> is true

therefore

Point C is a solution of the system of inequalities

Verify point D

F(3,4)

Inequality A

$x\geq2$ -----> $3\geq2$ ----> is true

Inequality B

$y\geq2$ ------> $4\geq2$ ----> is true

therefore

Point D is a solution of the system of inequalities

Part C: Natalie can only attend a school in her designated zone. Natalie's zone is defined by y < −2x + 2. Explain how you can identify the schools that Natalie is allowed to attend.

we have

$y < -2x+2$

The solution of the inequality is the shaded area below the dotted line $y=-2x+2$

The y-intercept of the dotted line is the point (0,2)

The x-intercept of the dotted line is the point (1,0)

To graph the inequality, plot the intercepts and shade the area below the dotted line

see the attached figure N 2

therefore

The schools that Natalie is allowed to attend are A,B and D

3 0

2 years ago

Plz help!!! due tonight I need help!!!!

Pachacha [2.7K]

Answer:

14400

Step-by-step explanation: i culd be wrong tho

3 0

2 years ago

Read 2 more answers

The table below shows the surface area y in square inches, of a shrinking puddle in x hours

Kruka [31]

Part A
Correlation coefficient: -.99
This tells us that as time goes on (value of x increases) the area of the puddle goes down (value of y decreases)

Part B
y₂ - y₁
------- = slope
x₂ - x₁
9 - 15
--------
5 - 8
-6/-3 = 2
So the slope equals -2, regardless of the fact that we got 2 as an answer there, we know that it is a negative slope

Part C
The data represents causation because an increase in the value of x results in a decrease in the value of y, this shows an example of direct causation between x and y.

8 0

3 years ago

Read 2 more answers

Assume that k and V0 are constant and are, respectively, 0.02, and 7. The parameter CA varies from an initial value CA0 = 100 to

julia-pushkina [17]

Answer:

V = 929.7

Step-by-step explanation:

Given the equation:

$\frac{dCA}{dV}$ = $\frac{-kCA}{V0}$