Let A(t) denote the amount of salt (in ounces, oz) in the tank at time t (in minutes, min).
Salt flows in at a rate of
[tex]\dfrac{dA}{dt}_{\rm in} = \left(17 (1 + 15 \sin(t)) \dfrac{\rm oz}{\rm gal}\right) \left(8\dfrac{\rm gal}{\rm min}\right) = 136 (1 + 15 \sin(t)) \dfrac{\rm oz}{\min}[/tex]
and flows out at a rate of
[tex]\dfrac{dA}{dt}_{\rm out} = \left(\dfrac{A(t) \, \mathrm{oz}}{180 \,\mathrm{gal} + \left(8\frac{\rm gal}{\rm min} - 8\frac{\rm gal}{\rm min}\right) (t \, \mathrm{min})}\right) \left(8 \dfrac{\rm gal}{\rm min}\right) = \dfrac{A(t)}{180} \dfrac{\rm oz}{\rm min}[/tex]
so that the net rate of change in the amount of salt in the tank is given by the linear differential equation
[tex]\dfrac{dA}{dt} = \dfrac{dA}{dt}_{\rm in} - \dfrac{dA}{dt}_{\rm out} \iff \dfrac{dA}{dt} + \dfrac{A(t)}{180} = 136 (1 + 15 \sin(t))[/tex]
Multiply both sides by the integrating factor, [tex]e^{t/180}[/tex], and rewrite the left side as the derivative of a product.
[tex]e^{t/180} \dfrac{dA}{dt} + e^{t/180} \dfrac{A(t)}{180} = 136 e^{t/180} (1 + 15 \sin(t))[/tex]
[tex]\dfrac d{dt}\left[e^{t/180} A(t)\right] = 136 e^{t/180} (1 + 15 \sin(t))[/tex]
Integrate both sides with respect to t (integrate the right side by parts):
[tex]\displaystyle \int \frac d{dt}\left[e^{t/180} A(t)\right] \, dt = 136 \int e^{t/180} (1 + 15 \sin(t)) \, dt[/tex]
[tex]\displaystyle e^{t/180} A(t) = \left(24,480 - \frac{66,096,000}{32,401} \cos(t) + \frac{367,200}{32,401} \sin(t)\right) e^{t/180} + C[/tex]
Solve for A(t) :
[tex]\displaystyle A(t) = 24,480 - \frac{66,096,000}{32,401} \cos(t) + \frac{367,200}{32,401} \sin(t) + C e^{-t/180}[/tex]
The tank starts with A(0) = 15 oz of salt; use this to solve for the constant C.
[tex]\displaystyle 15 = 24,480 - \frac{66,096,000}{32,401} + C \implies C = -\dfrac{726,594,465}{32,401}[/tex]
So,
[tex]\displaystyle A(t) = 24,480 - \frac{66,096,000}{32,401} \cos(t) + \frac{367,200}{32,401} \sin(t) - \frac{726,594,465}{32,401} e^{-t/180}[/tex]
Recall the angle-sum identity for cosine:
[tex]R \cos(x-\theta) = R \cos(\theta) \cos(x) + R \sin(\theta) \sin(x)[/tex]
so that we can condense the trigonometric terms in A(t). Solve for R and θ :
[tex]R \cos(\theta) = -\dfrac{66,096,000}{32,401}[/tex]
[tex]R \sin(\theta) = \dfrac{367,200}{32,401}[/tex]
Recall the Pythagorean identity and definition of tangent,
[tex]\cos^2(x) + \sin^2(x) = 1[/tex]
[tex]\tan(x) = \dfrac{\sin(x)}{\cos(x)}[/tex]
Then
[tex]R^2 \cos^2(\theta) + R^2 \sin^2(\theta) = R^2 = \dfrac{134,835,840,000}{32,401} \implies R = \dfrac{367,200}{\sqrt{32,401}}[/tex]
and
[tex]\dfrac{R \sin(\theta)}{R \cos(\theta)} = \tan(\theta) = -\dfrac{367,200}{66,096,000} = -\dfrac1{180} \\\\ \implies \theta = -\tan^{-1}\left(\dfrac1{180}\right) = -\cot^{-1}(180)[/tex]
so we can rewrite A(t) as
[tex]\displaystyle A(t) = 24,480 + \frac{367,200}{\sqrt{32,401}} \cos\left(t + \cot^{-1}(180)\right) - \frac{726,594,465}{32,401} e^{-t/180}[/tex]
As t goes to infinity, the exponential term will converge to zero. Meanwhile the cosine term will oscillate between -1 and 1, so that A(t) will oscillate about the constant level of 24,480 oz between the extreme values of
[tex]24,480 - \dfrac{267,200}{\sqrt{32,401}} \approx 22,995.6 \,\mathrm{oz}[/tex]
and
[tex]24,480 + \dfrac{267,200}{\sqrt{32,401}} \approx 25,964.4 \,\mathrm{oz}[/tex]
which is to say, with amplitude
[tex]2 \times \dfrac{267,200}{\sqrt{32,401}} \approx \mathbf{2,968.84 \,oz}[/tex]
The graph below shows the function f(x)=
x-3
+3
-2x-3•
The true statement about the graph is that there is a hole at x = 3 and an asymptote at x = -1.
How to explain the graph?The expression in the denominator is x^2-2x-3
x² - 2x-3 ≠0
-3 = +1 -4
(x²-2x+1)-4 ≠0
(x²-2x+1)=(x-1)²
(x-1)² - (2)² ≠0
∴a²-b² =(a-b)(a+b)
(x-1-2)(x-1+2) ≠0
(x-3)(x+1) ≠0
x≠3 for all x≠ -1
There is a hole at x=3 and an asymptote at x= -1, so Option B is wrong
Asymptote:
x-3/x^2-2x-3
We know that denominator is equal to (x-3)(x+1)
x-3/(x-3)(x+1)
x-3 will be cancelled out by x-3
1/x+1
We have asymptote at x=-1 and hole at x=3, therefore the correct option is A.
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Solve for height using the tangent method. Show your work.
Answer:
b = 17.318 height = 23.318 ft
Step-by-step explanation:
This IS very similar to the other one, Emily..... Have you tried to solve it the same way?
b = 152 tan 6.5 = 17.318 ft (using a calculator)
add the height of the victim's head (6 ft)
17.318 + 6 = 23.318 ft
2. Mr. Walters starts preparing breakfast at
6:45 AM. He finishes at 7:50 AM. How long
does it take for him to prepare breakfast?
Use the vectors to determine two dot products: u•v and u•w
u=9i-6j
v=-3i-2j
w=19i+15j
A
Take the product of corresponding components, then take the total:
u • v = (9i - 6j) • (-3i - 2j) = 9 (-3) + (-6) (-2) = -15
u • w = (9i - 6j) • (19i + 15j) = 9 × 19 + (-6) 15 = 81
Alternatively, use the definition and algebraic properties of the dot product.
• For any vector x,
x • x = ||x||²
where ||x|| is the magnitude of x.
• i • i = j • j = k • k = 1
• i • j = j • k = k • i = 0
• For any scalar c and any two vectors x and y,
cx • y = x • cy = c (x • y)
• For any vectors x, y, and z,
(x + y) • z = z • (x + y) = x • z + y • z
Then the products you want are
u • v = (9i - 6j) • (-3i - 2j)
… = -27 (i • i) + 18 (j • i) - 18 (i • j) + 12 (j • j)
… = -27 + 12 = -15
u • w = (9i - 6j) • (19i + 15j)
… = 171 (i • i) - 114 (j • i) + 135 (i • j) - 90 (j • j)
… = 171 - 90 = 81
On a popular television game show, a contestant must choose one of the five envelopes. One envelope contains the grand prize, a car. Find the probability of not choosing a car. Show your solution.
Urgent! Please answer immediately. The answers that are nonsense will be reported.
Answer:
4/5
Step-by-step explanation:
First, we know that we have 5 envelopes. So the denominator of the probability is going to be x/5. We then realize that only one envelope has the car, so the probability of that is 1/5. If we subtract 1/5 from the probability of choosing an envelope (5/5), we get 5/5-1/5=4/5.
Please help!
The price of products may increase due to inflation and decrease due to depreciation. Derek is studying the change in the price of two products, A and B, over time.
The price f(x), in dollars, of product A after x years is represented by the function below:
f(x) = 72(1.25)x
Part A: Is the price of product A increasing or decreasing and by what percentage per year? Justify your answer. (5 points)
Part B: The table below shows the price f(t), in dollars, of product B after t years:
t (number of years)
1 2 3 4
f(t) (price in dollars)
65 84.5 109.85 142.81
Which product recorded a greater percentage change in price over the previous year? Justify your answer. (5 points)
Answer:
A)25% B)Product B
Step-by-step explanation:
A) To find whether product A price is increasing or decreasing, we will find the difference in price between year 0 and 1 year after.
When x = 0,
f(0) [tex]72(1.25)^{0}\\= 72*1\\= 72[/tex]
when x = 1,
f(1) = [tex]72(1.25)^{1}\\= 72*1.25\\= 90[/tex]
From here we can already see the price is increasing.
% increase = (Difference in price / Original Price) * 100
= [tex]\frac{90-72}{72} *100\\=\frac{18}{72} *100\\=0.25*100\\=25percent[/tex]
Therefore the price is increasing by 25% per year.
B) Same concept as Part A, we will find the price difference between year 1 and 2.
% increase = (Difference in price / Original Price) * 100
[tex]\frac{84.5-65}{65} * 100\\= \frac{19.5}{65} * 100\\= 0.3*100\\= 30 percent[/tex]
Therefore we can see here Product B has a higher increase than Product A.
Step-by-step explanation:
A
f(x) = 72 × 1.25 × x
so, the price is $90 after 1 year (72×1.25×1).
$180 after 2 years (72×1.25×2)
$270 after 3 years (72×1.25×3)
and so on.
or did you mean
f(x) = 72 × (1.25)^x
so, still, the price is $90 after 1 year (72×1.25^1).
$112.50 after 2 years (72×1.25^2).
$140.625 = $140.63 after 3 years (72×1.25^3)
that makes more sense. I will continue with that assumption.
so, the price is increasing, as every factor of the multiplication is positive and larger than 1. therefore, it only goes up.
and due to the formula, the price of every year is the price of the previous year multiplied by 1.25.
a multiplication by 1.25 is an increase of 25% (compared to a constant multiplication by 1).
so, the price increases every year by 25%.
B
year 1
price $65
year 2
price $84.50 difference $19.50
100% = 65
1% = 65/100 = 0.65
19.5/0.65 = 30% difference
year 3
price $109.85 difference $25.35
100% = 84.5
1% = 84.5/100 = 0.845
25.35/0.845 = 30% difference
year 4
price $142.81 difference $32.96
100% = 109.85
1% = 109.85/100 = 1.0985
32.96/1.0985 = 30% difference
so, product B has the greater percentage increase in the price (30% vs. 25%).
I need help to find this number in scientific notation form pls.
Answer:
the answer is ( -0 ) ok?
Step-by-step explanation:
also my name ifs kris ik you from somewhere
i am very embarrest to say this but u are very pretty
are u single? im sorry if its freakish
are u mexican? of Philippians? im from la pearla tapatia mx hbu?
This net folds into the cube shown beside it. On the cube, which letter will be on the side opposite D?
B
A
E
C
The letter that will be on the side opposite D is letter B
How to determine the letter?The attached image represents the missing piece in the question
The opposite sides of a cube always have a face in between them, when represented as a net.
From the attached image, the adjacent sides are:
A B C D
F C E
The opposite sides as represented above are;
A and C
B and D
F and E
Hence, the letter that will be on the side opposite D is letter B
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Find the volume of the rectangular prism using the formula v = bh.
the area of the base, b, equals
___ cm2.
the volume of the prism is
___cm3.
Answer:
v=bh cm3 cm2 is not answer is 903cm2 23
explanation/proof why the lines are parallel and insights
Answer:
The lines are parallel is the will never touch.
Step-by-step explanation:
Please help me figure this out
Step-by-step explanation:
standard form is given by Ax × By = C
hence the answer would be
5x + 8y = 24
comment if you still have any doubts :)
Answer:
5x + 8y = 24
Step-by-step explanation:
Given :
[tex]y=-\frac{5x}{8} +3[/tex]
……………………
[tex]y=-\frac{5x}{8} +3[/tex]
[tex]\Longleftrightarrow 8\times y=8\times (-\frac{5x}{8} +3)[/tex]
[tex]\Longleftrightarrow 8y=-5x+24[/tex]
[tex]\Longleftrightarrow 5x+8y=24[/tex]
A number cube is rolled 14 times and the results are recorded in the table.
what, in simplest form, is the experimental probability that the number 4?
Answer:
2.3333 ≈ 2
Step-by-step explanation:
The first step is the 1/6 because you are only counting the value 4 not the other ones like 1,2,3,5,6. So then that is 0.1666666. Then you multiply it by 14 which is rounded to 2. I can tell you are a 6th grader.
DISCLAIMER: THIS ANSWER MAY BE FALSE BECAUSE THERE IS NO PICTURE ATTACHED TO THIS POST. THUS, NEXT TIME YOU SHOULD UPLOAD A PICTURE. THIS IS ONLY A GUESS NOT A REAL ANSWER.
please help the subject is exterior angles(triangles)
triangle png Find the value of x
Answer:
x+3x+2x=180(sum of triangle)
6x=180
x=180/6
x=30
again
3x=3×30=90
2x=2×30=60
Jamal has run 7 miles from point a to point b of a race. the entire race from point a to point c is 26 miles. how many
more miles will he run to complete the race?
The number of more miles he needs to run to complete the race is 19 miles.
How to find distance in miles?He has run 7 miles from point a to point b of a race.
The entire race from point a to point c is 26 miles.
Therefore, the number of more miles he needs to run to complete the race is as follows:
let
x = the more miles he needs to run
Hence,
x = 26 - 7
x = 19 miles
Therefore, he needs to run 19 more miles to complete the race.
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As one of the grade 9 top performing students competing for the “Boy Scout of the Year” award, you are assigned by your scoutmaster to design a camping site for the coming Boy Scout in-door camping. You have to maximize the area at which the 20 scouts can assemble their own tents. The tents should be equally spaced and must be situated at the same distance of 20 m from the tent of the scout master, which is located at the center of the scouts. The angle at which the tents are positioned from the scoutmaster should be approximately the same. Would you know how far apart the tents of the scouts are from each other?
Answer:
Yes you would know
Step-by-step explanation:
We can view these tents as sides on a shape that is 30 sided, with lines connecting each tents together.
After this we calculate the interior angle of each side, and use our given 20m to calculate it.
temp change -4.2 and 9.1
Subtraction is a mathematical operation that reflects the removal of things from a collection. The temperature change from -4.2 to 9.1 is 13.3.
What is subtraction?Subtraction is a mathematical operation that reflects the removal of things from a collection. The negative symbol represents subtraction.
The temperature change from -4.2 to 9.1 is,
ΔT = 9.1 - (-4.2) = 9.1 + 4.2 = 13.3
Hence, the temperature change from -4.2 to 9.1 is 13.3.
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Expand: In (4a)^3
help please
Answer: 3ln4 + 3lna
Step-by-step explanation:
[tex]\ln (4a)^{3}\\=3 \ln 4a\\=3(\ln 4+\ln a)\\=\boxed{3\ln 4+3\ln a}[/tex]
Answer:
C and second one is A
what is the area of this rectangle
Answer:
6 cm^2
Step-by-step explanation:
Area of Rectangle is L*W
L=3 and W=2
3*2=6
100 POINTS!!! REPOST!!! NEED HELP!!! NO SPAMMING!!!
(Refer to the attached image)
============================================================
Explanation:
I'm going to relabel the figure as triangle ABC.
As the instructions mention, we'll use the law of cosines to find the missing side.
side a = 147side b = 166angle C = 50 degreesUse these facts to find side c
c^2 = a^2 + b^2 - 2*a*b*cos(C)
c^2 = 147^2 + 166^2 - 2*147*166*cos(50)
c^2 = 17794.393497
c = sqrt(17794.393497)
c = 133.395628
c = 133
PLEASE HELP!! ITS URGENT!!
Find all solutions to the equation 3 cos (5t) + 3 = 2 in the interval
ㅠ
0≤t≤ radians.
a) 0.3821, 0.2462, 0.8745
b) 0.654
c) 0.3821, 0.8745
d) No solutions in the interval.
All solutions to the equation 3 cos (5t) + 3 = 2 in the interval from 0 to π will be 0.3821, 0.2462, and 0.8745. Then the correct option is A.
What is trigonometry?The connection between the lengths and angles of a triangular shape is the subject of trigonometry.
The equation is given below.
3 cos (5t) + 3 = 2
By simplifying the equation, then we have
3 cos 5t = -1
cos 5t = -1/3
Then the value of t will be
5t = 1.91063, 1.12096, 4.3725
t = 0.3821, 0.2462, 0.8745
Then the correct option is A.
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What expression lets us conclude that the parts of congruent triangles are congruent to each other?
Corresponding Parts of Congruent Triangles are Congruent
Congruent Triangles have Congruent Parts
Opposite parts of Congruent Triangles are Similar
The expression that allows us conclude parts of congruent triangles are congruent to each other is corresponding parts of Congruent Triangles are congruent
What are congruent triangles?A triangle is a three-sided polygon with three edges and three vertices. the sum of angles in a triangle is 180 degrees. Two triangles are congruent when they have exactly the same three sides and exactly the same three angles.
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Write a nuclear formula for 37^Ca
Answer:
37
20
C
a
→
37
19
K
+
0
+
1
e
This equation shows us the parent atom, which is calcium-37. The mass number is written above the atomic number for the atom. The arrow indicates the decay process with the products to the right of the arrow. The products are an atom of potassium-37 and a positron, which is similar to an electron but it carries a charge of +1 instead of a charge of -1. We can see that the transition of a proton to a neutron in positron decay decreases the atomic number of the atom from 20 to 19, but the mass number of 37 remains the same.
Step-by-step explanation:
Answer:
37
20
C
a
→
37
19
K
+
0
+
1
e
Step-by-step explanation:
does someone mind helping me with this question? Thank you!
Answer:
70
Step-by-step explanation:
ok so we just plug 4 for x in the expression:
5 (2*4 + 6 )
5 ( 8 + 6 )
5*14 = 70
Have a good day! :)
Julia surveyed twenty households on her street to determine the average number of children living in each household. the tables below represent the collected data and a randomly selected sample from the population. compare the mean of the population with the mean of the sample. population data 0 3 3 1 3 2 2 2 5 4 3 3 3 0 1 2 0 2 3 3 sample data 5 3 0 2 4 what is the difference between the mean of the sample and the mean of the population? 0.55 1.25 2.25 2.80
The difference between the mean of the sample and the mean of the population is A. 0.55
Calculations and Parameters:Given the population data is:
0 3 3 1 3 2 2 2 5 4 3 3 3 0 1 2 0 2 3 3
The sample data is:
5 3 0 2 4
The mean of the population data is:
45/20= 2.25
The mean of the sample data is:
14/5= 2.8
Therefore, the difference between the mean of the sample and the population is:
2.8-2.25= 0.55
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What is the area of the following circle
Answer:
Area = 153.86
Step-by-step explanation:
Formula: A = [tex]\pi r^{2}[/tex]
diameter (d) = 14
radius = d / 2
radius is 14 / 2 = 7
A = [tex]\pi (7)^{2}\\\pi 49\\49\pi \\49(3.14) = 153.86[/tex]
100 POINTS PLEAS please help
(-2u3 + 5u - 1) + (7u3 - 2u2 + 9)
A) 5 u3 - 2 u2 + 5 u + 8
B) -5 u3 - 2 u2 + 5 u + 10
C)5 u3 + 3 u + 8
Answer:
[tex]\textsf{A)} \quad 5u^3-2u^2+5u+8[/tex]
Step-by-step explanation:
Given expression:
[tex](-2u^3+5u-1)+(7u^3-2u^2+9)[/tex]
Remove parentheses:
[tex]\implies -2u^3+5u-1+7u^3-2u^2+9[/tex]
Collect like terms:
[tex]\implies -2u^3+7u^3-2u^2+5u-1+9[/tex]
Combine like terms:
[tex]\implies 5u^3-2u^2+5u+8[/tex]
Option A
Regina’s work to find the surface area of a square pyramid from its net is shown below.
A square pyramid. The square base has side lengths of 9.4 inches. The triangular sides have a height of 11.9 inches.
Surface area of the pyramid = 4 (one-half (9.4) (12.8)) + 9.4 squared = 329 square inches
What error did Regina make?
She should have used One-half (9.4) (11.9) to represent the area of a single triangle.
She should have multiplied all the terms inside the parentheses by 4 when she simplified.
She should have used One-half (4.7) (12.8) to represent the area of a single triangle.
She should have used a different collection of shapes as the net of the pyramid.
She put 12.8 in place of 11.9 in the formula of the triangle. Then the correct option is A.
What is Geometry?It deals with the size of geometry, region, and density of the different forms both 2D and 3D.
Regina’s work to find the surface area of a square pyramid from its net is shown below.
A square pyramid. The square base has side lengths of 9.4 inches. The triangular sides have a height of 11.9 inches.
Surface area of the pyramid = 4 [one-half (9.4) (12.8)] + 9.4² = 329 square inches
Then the error done by Regina will be
She should have used One-half (9.4) (11.9) to represent the area of a single triangle.
Then the correct option is A.
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Answer:
A
Step-by-step explanation:
Donations to an annual fundraiser are 15% greater this year than last year. Last year, donations were 10% greater than the year before. The amount raised this year is $10,120. How much was raised two years ago?
Answer:
8000.
Step-by-step explanation:
um I said so you don't need no step by step.
Please help me!
Explain how to use the graphs of systems of equations to state when the system has one solution, no solution, or infinite solutions. Be specific.
Explanation:
The solution set for a system of equation is the set of points where the graphs of the equations intersect.
__
general caseA system will have one solution if there is a single point of intersection of the graphs of the equations.
A system will have no solutions if the graphs have no points of intersection.
A system will have an infinite number of solutions if the graphs intersect at an infinite number of points.
_____
linear equationsWhen the equations are linear equations, their graphs are straight lines. If the lines have different slopes, they must intersect at exactly one point: there will be one solution.
If the lines have the same slope, there are two possibilities:
the lines are parallel -- no solutionsthe lines are coincident -- infinite solutionsThe attached graph illustrates these cases.
the red and blue lines are the graphs of a system of equations with one solution. Those lines have different slopesthe blue and green lines are the graphs of a system of equations with no solution. Those lines are parallel.The red and (dotted) purple lines are the graphs of a system of equations with infinite solutions. Those lines are coincident.