A building has an entry the shape of a parabolic arch 84 ft high and 42 ft wide at the base, as shown below. A parabola opening down with vertex at the origin is graphed on the coordinate plane. The height of the parabola from top to bottom is 84 feet and its width from left to right is 42 feet. Find an equation for the parabola if the vertex is put at the origin of the coordinate system. (

Answers

Answer 1

Answer:

Step-by-step explanation:

Because of the nature of the information we are given, we have no choice but to use the equation

[tex]y=a(x-h)^2+k[/tex]

and solve for a.

We know by the info that the vertex is (0, 84). We also know that if the vertex is at the origin, and that the base is 42 feet wide, it spans 21 feet to the right of the origin and 21 feet to the left of the origin. That means that we have 2 coordinates from which we need to pick one for our x and y in the equation. I don't like negatives, so I am going to choose the coordinate (21, 0) as x and y. Because this parabola opens upside down, as archways of door openings do, our "a" value better come out algebraically as a negative. Let's see...From the vertex we have that h = 0 and k = 84. So filling in:

[tex]0=a(21-0)^2+84[/tex] and simplifying a bit:

0 = 441a + 84 and

-84 = 441a so

[tex]a=-\frac{84}{441}=-\frac{4}{21}[/tex] Good, a is negative. Your equation is, then:

[tex]y=-\frac{4}{21}x^2+84[/tex]

Answer 2

Answer:

x² = -21y

Step-by-step explanation:

THIS IS THE RIGHT ANSWER I TOOK THE TEST


Related Questions

Could you help with maths please? All shown on the picture :)

Answers

Answer:

4 is tenths (a) and 5 is hundredths (b)

Step-by-step explanation:

Now, 0.45

0 indicates the ones place (it comes before the decimal)

0.45 can also be written as:

0.4+0.05

= 4/10+5/100

what can we conclude from this?

we can say that 4 is in the tenths whilst 5 is in the hundredths.

therefore, a is 4 and b is 5.

Hope this helps you! :)

30 PTS!! Can someone PLEASE rephrase this? The compass and straightedge is more important in constructing geometric structures than other drawing tools such as rulers and protractors. Because steps taken with a compass and straightedge cannot be seen at first glance and this situation become a problem for students.

Answers

Answer:

Step-by-step explanation:

This study investigated three mathematics teachers' construction process of geometric structures using compass and straightedge. The teacher-student-tool interaction was analysed. The study consists of the use of a compass and straightedge by the teachers, the ideas of the teachers about their use, and the observations regarding the learning process during the construction of the geometric structures. A semi-structured interview was conducted with the teachers about the importance of the use of a compass and straightedge to construct geometric structures. It was found that teachers taught compass and straightedge constructions in a rote manner where learning is little more than steps in a process. The study concludes with some suggestions for the use of a compass and straightedge in mathematics classes based on the research results. SUMMARY Purpose and significance: For more than 2,000 years, the way in which geometric structures could be constructed with the help of compasses and straightedges has caught the attention of mathematicians. Nowadays, mathematics curriculums place an emphasis on the use of the compass and straightedge. The compass and straightedge is more important in constructing geometric structures than other drawing tools such as rulers and protractors. Because steps taken with a compass and straightedge cannot be seen at first glance and this situation become a problem for students. However, 'doing compass and straightedge construction early in the course helps students to understand properties of figures'

A triangle and the coordinates of its vertices is shown in the coordinate plane below. Enter the area of this triangle in square units, rounded to the nearest tenth. square units

Answers

Answer:

22 units²

Step-by-step explanation:

1/2b*h=area

You can either count the units or use the distance formula.

[tex]d = \sqrt{ {(x2 - x1)}^{2} + {(y2 - y1)}^{2} } [/tex]

b = 4 units

h = 11 units

area = (1/2*4)*11 = 22 units²

Polygon ABCD is defined by the points A(-4, 2), B(-2, 4), C(1, 3), and D(2, 2). Match the coordinates of the points of the transformed polygons to their correct values. the coordinates of D′ if polygon ABCD rotates 90° counterclockwise to create A′B′C′D′ (-2, 2) the coordinates of C″ if polygon ABCD rotates 90° clockwise to create A″B″C″D″ (4, -2) the coordinates of A′′′ if polygon ABCD rotates 180° clockwise to create A′′′B′′′C′′′D′′′ (3, -1) the coordinates of B″ if polygon ABCD rotates 270° counterclockwise to create A″B″C″D″ (4, 2)

Answers

Answer:

The coordinates of D′ if polygon ABCD rotates 90° counterclockwise to create A′B′C′D′ is at (-2, 2)

The coordinates of C″ if polygon ABCD rotates 90° clockwise to create A″B″C″D″ is at (3, -1)

The coordinates of A′′′ if polygon ABCD rotates 180° clockwise to create A′′′B′′′C′′′D′′′ is at (4, -2)

The coordinates of B″ if polygon ABCD rotates 270° counterclockwise to create A″B″C″D″ is at (4, 2)

Step-by-step explanation:

A transformation is the movement of a point from its initial position to a new position. If a shape is transformed, all its points are also transformed. Types of transformation are reflection, rotation, dilation and translation.

Given Polygon ABCD is defined by the points A(-4, 2), B(-2, 4), C(1, 3), and D(2, 2).

If a point X(x, y) is rotated 90° counterclockwise, the new location X' is at (-y, x)

If a point X(x, y) is rotated 90° clockwise, the new location X' is at (y, -x)

If a point X(x, y) is rotated 180° clockwise, the new location X' is at (-x, -y)

If a point X(x, y) is rotated 270° counterclockwise, the new location X' is at (y, -x)

The coordinates of D′ if polygon ABCD rotates 90° counterclockwise to create A′B′C′D′ is at (-2, 2)

The coordinates of C″ if polygon ABCD rotates 90° clockwise to create A″B″C″D″ is at (3, -1)

The coordinates of A′′′ if polygon ABCD rotates 180° clockwise to create A′′′B′′′C′′′D′′′ is at (4, -2)

The coordinates of B″ if polygon ABCD rotates 270° counterclockwise to create A″B″C″D″ is at (4, 2)

Answer:

Transformation is the movement of a point from its initial location to a new location. Types of transformation are rotation, reflection, translation and dilation.

If a point A(x, y) is rotated 90° counterclockwise, the new point is at A'(-y, x).

If a point A(x, y) is rotated 90° clockwise, the new point is at A'(y, -x). If a point A(x, y) is rotated 180° counterclockwise, the new point is at A'(-x, -y).

If a point A(x, y) is rotated 270° counterclockwise, the new point is at A'(y, -x).

Polygon ABCD is defined by the points A(-4, 2), B(-2, 4), C(1, 3), and D(2, 2).

The coordinates of D′ if polygon ABCD rotates 90° counterclockwise to create A′B′C′D′ is D'(-2, 2)

The coordinates of C″ if polygon ABCD rotates 90° clockwise to create A″B″C″D″ is C"(3, -1).

The coordinates of A′′′ if polygon ABCD rotates 180° clockwise to create A′′′B′′′C′′′D′′′ is A''"(4, -2)

The coordinates of B″ if polygon ABCD rotates 270° counterclockwise to create A″B″C″D″ is B"(4, 2)

Find the slope and the y-intercept of the line.
- 8x+4y=-4
Write your answers in simplest form.
slope:
.
08
Undefined
X
$
?
y-intercept: 1

Answers

Answer:

slope - (2x)

y-intercept - (-1)

Step-by-step explanation:

-8x + 4y = - 4

4y = 8x - 4

y = 2x - 1

Please help!
Suppose that [tex]\alpha[/tex] is inversely proportional to [tex]\beta[/tex]. If [tex]\alpha=4[/tex] when [tex]\beta=9[/tex], find [tex]\alpha[/tex] when [tex]\beta=-72[/tex]

Answers

Answer:

The answer is

[tex] \alpha = - \frac{1}{2} [/tex]

Step-by-step explanation:

From the question

[tex]\alpha[/tex] is inversely proportional to [tex]\beta[/tex] is written as

[tex] \alpha = \frac{k}{ \beta } [/tex]

where k is the constant of proportionality

When

[tex]\alpha[/tex] = 4[tex]\beta[/tex] = 9

Substituting the values into the formula

we have

[tex]4 = \frac{k}{9} [/tex]

cross multiply

k = 4 × 9

k = 36

So the formula for the variation is

[tex] \alpha = \frac{36}{ \beta } [/tex]

when

[tex]\beta[/tex] = - 72

That's

[tex] \alpha = \frac{36}{ - 72} [/tex]

Simplify

We have the final answer as

[tex] \alpha = - \frac{ 1}{2} [/tex]

Hope this helps you

A school system is reducing the amount of dumpster loads of trash removed each week. In week 5, there were 40 dumpster loads of waste removed. In week 10, there were 30 dumpster loads removed. Assume that the reduction in the amount of waste each week is linear. Write an equation in function form to show the amount of trash removed each week. A f(x) = −2x + 40. B f(x) = 2x + 40 C f(x) = −2x + 50 D f(x) = 2x + 50

Answers

Answer:

The answer is A f(x) = -2x + 40

Step-by-step explanation:

it has a negative 2 because the dumps are decreasing by 2 every week and x is the amount of weeks and + 40 because that is the amount you started with.

Point B is on line segment AC. Given BC=9 and AB=11, determine the length AC.

Answers

Answer:

20

Step-by-step explanation:

If point B is on line segment AC, then we know for sure AB + BC = AC.

To understand this better, draw a line segment, then put a point anywhere on the line segment. There are two line segment divided by that point. If you combine those two line segments then you have your original figure.

So 11 + 9 = 20.

Solving Inequalities and graphing them.

Answers

Answer:

I used to know this not anymore sry g

A 250.0 kg rock falls off a 40.0 m cliff. What is the kinetic energy of the rock just before it hits the ground (hint: conservation of energy)?

Answers

Answer:

kinetic energy body when it hits the ground is 98000 joule

1000joule = 1 kilojoule

, kinetic energy body when it hits the ground is 98  kilo-joule

Step-by-step explanation:

conservation of energy states that total energy of a system remains constant.

Potential energy of body = mgh

m = mass

g = gravitational pull = 9/8 m/s^2

h = height

kinetic energy = 1/2 mv^2

where v is the velocity of body

________________________________________

Total energy for this at any point is sum of potential energy and kinetic energy

total energy at height h

v= 0

PE = 250*9.8*40= 98,000

KE = 1/2 m0^2  = 0

total energy at when ball hits the ground

h=0

PE = 250*9.8*0 =

KE = 1/2 mv^2  

_______________________________________\

Applying conservation of energy

Total energy at height h = total energy at ground

98000 = KE

Thus, kinetic energy body when it hits the ground is 98000 joule

1000joule = 1 kilojoule

, kinetic energy body when it hits the ground is 98  kilo-joule

Jonas needs a cell phone. He has a choice between two companies with the following monthly billing policies. Each company’s monthly billing policy has an initial operating fee and charge per text message. Sprint charges $29.95 monthly plus .15 cents per text, AT&T charges $4.95 monthly plus .39 cents per text. Create equations for the two cell phone plans.

Answers

Answer:

Since both companies have a different plan, two equations are created to determine which company Jonas should choose with respect to the number of messages sent.

Step-by-step explanation:

- Sprint = $ 29.95 * X (0.15)

- AT & T = $ 4.95 * X (0.39)

One dollar equals 100 cents, so 0.15 cents equals $ 0.0015 dollars.

- Sprint = $ 29.95 * X (0.0015)

- AT & T = $ 4.95 * X (0.0039)

Si Jonas envía 500 mensajes de texto el valor mensual de cada empresa sería de:

- Sprint = $ 29.95 * 500 (0.0015)  = 22.46 dollar per month.

- AT & T = $ 4.95 * 500 (0.0039)  = 9.65 dollar per month.

The company Jonas should choose is AT&T.

AT&T also charges a little more per number of text messages, but since the phone's value is so low it would take thousands of text messages to compare to Sprint's monthly value.

HELP HELP HELP Sally can paint a room in 4 hours. Joe can paint a room in 6 hours. How
long will it take if they paint the room together? I’m not sure if it’s 1.4

Answers

Answer:

2 hrs, 24 min

Step-by-step explanation:

Sally:  in one hour, she can paint 1/4 of the room.

Joe: in one our, he can paint 1/6 of the room

Hour one: 1/4+1/6=3/12+2/12=5/12

1÷5/12=1*12/5=12/5

12/5= 2 & 2/5 hours, or 2.4 hours, or 2 hrs 24 minutes

Answer: 2.4 hours

Step-by-step explanation:

1/4 1/6

LCM

3/12+2/12=5/12 repricical 12/5 =2.4

Solve for x. 23x +2=15x+48x+6

Answers

Answer:

[tex]x = - \frac{1}{10} [/tex]

Step-by-step explanation:

23x +2 = 15x+48x+6

To solve for x group like terms

That's

Send the constants to the right side of the equation and those with variables to the left side

We have

23x - 15x - 48x = 6 - 2

Simplify

- 40x = 4

Divide both sides by -40

[tex] \frac{ - 40x}{ - 40} = \frac{4}{ - 40} [/tex]

We have the final answer as

[tex]x = - \frac{1}{10} [/tex]

Hope this helps you

If you simplify both sides, it shows that 23x+2=63x+6. If you cancel out the x, it shows that 2=40x+6. If you cancel out the numbers it shows that -4=40x. Divide all sides to show that -1/10=x.

A trader buys tea for $1200 and sells it for $1500. Per sack of tea he makes a profit of $50. How many sacks of tea did he have?

Answers

Answer:

6 sacks

Step-by-step explanation:

Buying Price = $1200

Selling Price = $1500

Total profit = Selling price - Buying Price

= $1500 - $1200

= $300

Given that the profit on each sack of tea is $50

Number of Sacks of Tea = Total Profit ÷ profit per sack

= $300 ÷ 50

= 6 sacks

The number of sacks of tea he has is 6.

The first step is to determine the total profit earned by the trader. Profit is the selling price less the cost price.

Profit = selling price - cost price

$1500 - $1200 = $300

The second step is to divide the total profit by the profit made per sack of tea.

Number of sacks = $300 / $50 = 6

To learn more about division, please check: https://brainly.com/question/194007

The product of 2 rational numbers is -16/9 . If one of the numbers is -4/3 find the other plz fast

Answers

Answer:

4/3

Step-by-step explanation:

let the other number be x.

-4/3 x=-16/9

x=-16/9×-3/4=4/3

If P = (3,4), Find: Rx=1 (P)

Answers

Answer:

-1, 4

Step-by-step explanation:

Answer:

Step-by-step explanation:

answer is (-1,4)

Solve x∕4 + y∕3 = 1 for x.

Answers

Answer:

x = [tex]\frac{12-4y}{3}[/tex]

Step-by-step explanation:

Given

[tex]\frac{x}{4}[/tex] + [tex]\frac{y}{3}[/tex] = 1

Multiply through by 12 to clear the fractions

3x + 4y = 12 ( subtract 4y from both sides )

3x = 12 - 4y ( divide both sides by 3 )

x = [tex]\frac{12-4y}{3}[/tex]

A man traveled to his country home, a distance of 150 miles and then back. His average rate of speed going was 50 miles an hour and his average return speed was 30 miles per hour. His average rate of speed for the entire trip was Need help will mark brainlist

Answers

Answer:

  37.5 mi/h

Step-by-step explanation:

  time = distance / speed

On the trip 'going', the time was (150 mi)/(50 mi/h) = 3 h.

On the return trip, the time was (150 mi)/(30 mi/h) = 5 h.

__

  speed = distance / time

The average speed for the whole trip was ...

  speed = (150 mi +150 mi)/(3 h +5 h) = (300 mi)/(8 h) = 37.5 mi/h

His average rate of speed was 37.5 miles per hour.


Use the least common denominator of 10 and 15 to solve 2/10+7/15 .

Answers

Answer: 2/3

Step-by-step explanation: As you can see, the denominators are different so we need to find a common denominator to add these 2 fractions.

We find the common denominator by finding

the common multiple for these 2 denominators.

Multiples of 10

1 x 10 = 10

2 x 10 = 20

3 x 10 = 30

Multiples of 15

1 x 15 = 15

2 x 15 = 30

As you can see, we have a common multiple of 30.

To get 30 in the denominator of 2/10, multiply top and bottom by 3.

To get 30 in the denominator of 7/15, multiply top and bottom by 2.

So we have 6/30 + 14/30 which is 20/30.

20/30 can be reduced to 2/3.

if the gradient of the line joining the points [4,-9]and [-3,h]is -3, find the value of H

Answers

Answer:

h = 12

Step-by-step explanation:

To find the value of h use the formula for finding the slope of a line

That's

[tex]m = \frac{y2 - y1}{x2 - x1} [/tex]

Where ( x1, y1) and (x2 ,y2) are the points

From the question

slope = - 3

The points are [4,-9] and [-3,h]

Substitute these values into the equation

We have

[tex] - 3 = \frac{h + 9}{ - 3 - 4} [/tex]

[tex] - 3 = \frac{h + 9}{ - 7} [/tex]

Cross multiply

That's

- 3(-7) = h + 9

21 = h + 9

h = 21 - 9

We have the final answer as

h = 12

Hope this helps you

Bob has taken out a loan of $15,000 for a term of 48 months (4 years) at an interest rate of 6.5%. Using the amortization table provided, what will be his total finance
charge over the course of his loan?
Monthly Payment per $1,000 of Principal
Rate 1 Year 2 Years 3 Years 4 Years 5 Years
6.5% $86.30 $44.55 $30.65 $23.71 $19.57
7.0% $86.53 $44.77
$30.88
$23.95
$19.80
7.5% $86.76 $45.00
$31.11
$24.18
$20.04
8.0% $86.99 $45.23
$31.34
$24.41
$20.28
8.5% $87.22 $45.46
$24.65
$24.65
$20.52
9.0% $87.45 $45.68
$31.80
$24.89
$20.76
A.
$355.65
O
B.
$975.00
C.
$1,682.40
D.
$2,071.20
E. $17,071.20
Reset
Next
© 2020 Edmentum. All rights reserved.​

Answers

Answer:

  D.  $2071.20

Step-by-step explanation:

The table tells you that Bob's monthly payment on a 4-year loan at 6.5% will be $23.71 per thousand borrowed. The sum of those 48 payments is ...

  48 × $23.71 = $1138.08

That means, Bob pays $138.08 in total finance charge for each $1000 he borrows. He is borrowing 15 times $1000, so his total finance charge will be ...

  finance charge = 15 × $138.08 = $2071.20 . . . matches choice D

6) By which least number should each of the following numbers be divided to make them perfect squares?
a) 3920

Answers

3920|2

1960|2

980|2

490|2

245|5

49|7

7|7

1

[tex]3920=2^4\cdot5\cdot7^2=(2^2)^2\cdot5\cdot7^2[/tex]

It's 5

 If 2x3 – 4x2 + kx + 10 is divided by (x + 2), the remainder is 4. Find the value of k using remainder theorem. Please help :)​

Answers

The polynomial remainder theorem states that the remainder of the division of a polynomial [tex]P(x)[/tex] by [tex]x-a[/tex] is equal to [tex]P(a)[/tex].

Therefore

[tex]P(-2)=4\\2\cdot(-2)^3 - 4\cdot(-2)^2 + k\cdot(-2) + 10=4\\-16-16-2k=-6\\-2k=26\\k=-13[/tex]

Plz help me with this problem guys

Answers

The length of LM Left and M

multiplying polinomiyal(5x+2)(3x+4)​

Answers

Answer:

(5x+2) (3x+4)

= 15x²+20x+6x+8

= 15 x²+ 26x+8

Hope this helps ^_^

Answer:

Step-by-step explanation:

Use FOIL method

(5x + 2)(3x + 4) = 5x * 3x + 5x *4 + 2*3x +2*4

                        = 15x² + 20x + 6x + 8    { now add like terms}

                       = 15x² + 26x + 8

4x + 5 = x + 26​ need help

Answers

Answer:

x = 7

Step-by-step explanation:

4x + 5 = x + 26

4x - x = 26 - 5

3x = 21

x = 21/3

x = 7

Check:

4*7 + 5 = 7 + 26

28 + 5 = 33

I don’t really understand this

Answers

Answer

pretty sure its a or c, sorry I cant be more specific

Step-by-step explanation:

I need help answering these two questions

Answers

Answer:

Step-by-step explanation:

1. Area=3b*b=300 inches^2

  3b^2=300

  :3         :3

  b^2=100

 b=V100inches ^2

b=10 inches

2. Area=4b*3b

  so 12b^2=4800

        :12        :12

      b^2=400

     b=V400

    b=20 inches

                             

10 points to the person who answers this question.

Answers

Answer:

your answer is

2 X l+b

2 X 6x + 3x

8x + 10...

What is the 6th row of Pascal's triangle?

Answers

Answer:

1, 6, 15, 20, 15, 6, 1

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