Given the directrix of y = 4 and focus of (0, 2), which is the equation of the parabola?

Answer:

Step-by-step explanation:

This is a super simple problem. I'm going to walk through it as I do when I teach this to my students for the first time.

We are given a rectangle. We are told to find how fast the area is changing under certain conditions. That tells us that the main equation for this problem is the area formula for a rectangle which is

[tex]A=lw[/tex]. If we are looking for the rate at which the rectangle's area is changing, that means that we need to find the derivative of the area implicitly. This derivative is found using the product rule because the length is being multiplied by the width:

[tex]\frac{dA}{dt}=l\frac{dw}{dt}+w\frac{dl}{dt}[/tex] . If our unknown is the rate at which the area is changing, [tex]\frac{dA}{dt}[/tex], that means that everything else has to have a value (because you can only have one unknown in an equation). Here's what we're told:

The length of the rectangle is increasing at a rate of 7 cm/s, so that satisfies our [tex]\frac{dl}{dt}[/tex];

the width is increasing at a rate of 6 cm/s, so that satisfies our [tex]\frac{dw}{dt}[/tex];

and all of this is going on when the length = 12 and the width = 8. It looks like everything will have a value except for our unknown. Filling in:

[tex]\frac{dA}{dt}=12(6)+8(7)[/tex] and

[tex]\frac{dA}{dt}=72+56[/tex] so

[tex]\frac{dA}{dt}=128\frac{cm^2}{s}[/tex]

Answer:

The time required is 60.3 days.

Step-by-step explanation:

initial amount, No = 0.3 g

rate, r = 1.15 % per day = 0.0115 per day

final amount, N = 0.15 g

Let the time is t.

[tex]N = No e^{-rt}\\\\0.15 = 0.3 e^{-0.0115 t}\\\\0.5 =e^{-0.0115 t}\\\\- 0.6931 = - 0.0115 t \\\\t = 60.3 days[/tex]

Answer:

Four places to the left.

Step-by-step explanation:

14.6/10000

=> 1.46/1000 [Shifted 1 decimal place after dividing by 10]

=> 0.146/100 [Shifted 1 decimal place after dividing by 10]

=> 0.0146/10 [Shifted 1 decimal place after dividing by 10]

=> 0.00146   [Shifted 1 decimal place after dividing by 10]

Number of decimal places = 1+1+1+1=4

Four places to the left.

Answer:

3.418

Step-by-step explanation:

3.4175

3.4178

u round if the number behind it is higher than 5

Answer:

marilyn isrestiring and wants to set up a 25-year annuity earns 7.

A line of symmetry would separate a shape to make multiple shapes that are exactly the same.

The answer is C.2

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Answer:

  120

Step-by-step explanation:

I find it pretty easy to obtain the solution by graphing ...

  c(x) -13865 = 0

The positive value of x that makes this so is x = 120.

120 units will have a cost of 13,865 to manufacture.

__

If you like to solve this algebraically, you can probably do it most easily by completing the square.

  x^2 -5x = -65 +13865

  x^2 -5x +6.25 = 13806.25 . . . . . add the square of (-5/2)

  (x -2.5)² = 13806.25

  x -2.5 = √13806.25 = 117.5 . . . . only the positive square root is interesting

  x = 117.5 +2.5 = 120

Answer:

A. Increase speed to approximately 7.1 mph so that you cover the field more.

Step-by-step explanation:

The soil samples for the next field require more fertilizer coverage therefore there is need for more field coverage by the equipment. The speed of the tractor will be increase to 7.1 mph so that greater area can be covered in lesser time.

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Answer:

Step-by-step explanation:

We observe that the second equation of System B has had the x-term eliminated. That can be accomplished by adding 3 times the first equation to the second.

"To get System B, the second equation in System A was replaced by the sum of that equation and 3 times the first equation. The solution is the same as the solution to System A."

If one ball is selected at random, the odds for it being striped are 7 out of 15, or 7/15.

What do we know?

We know that there are 15 billiard balls.

We also know that balls numbered 1 through 8 are solid-colored, so we have 8 solid-colored balls.

And the other 7 balls are striped.

Now we want to find the probability for a randomly selected ball to be a striped ball.

Because all the balls have the same probability of being randomly selected, the probability of randomly selecting a striped ball is equal to the quotient between the number of striped balls (7) and the total number of balls (15).

Then we have:

P = 7/15 = 0.467

That quotient is also what is called the "odds"

So if one ball is selected at random, the odds for it being striped are 7 out of 15, or 7/15.

If you want to learn more, you can read:

https://brainly.com/question/23044118

Answer:

1) x+y=-2

x=-2-y

2) x-y=-8

substitude value of x

(-2-y)-y=-8

-2-2y=-8

-2y=-6

y=3

Substitute value of y in 1

x=-2-3

x=-5

Brainliest please~

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Answer:

  12

Step-by-step explanation:

Apparently, you want the sum a+b when ...

  [tex]\[\displaystyle\frac{\sqrt{600} + \sqrt{150} + 4\sqrt{54}}{6\sqrt{32} - 3\sqrt{50} - \sqrt{72}} = a\sqrt{b},\][/tex]

A calculator can show you the expression on the left evaluates to √243. In simplest terms, that is 9√3, so we have a=9, b=3 and ...

  a+b = 9+3 = 12

Answer:

12

Step-by-step explanation:

Hello!

f(g(x)) = 4 - 2 × (3x²) <=>

<=> f(g(x)) = 4 - 6x²

Answer: B. f(g(x)) = 4 - 6x²

Good luck! :)

Let we find the composition,

→ f(g(x)) = 4 (-2 × 3x²)

→ f(g(x)) = 4 -6x²

Hence, option (B) is the answer.

Answer:

below

Step-by-step explanation:

hope it is well understood?

The slope is 4 and y- intercept is 13

A number that describes a line's direction and steepness is known as the slope or gradient of a line in mathematics.

A slope exists Numerical calculation of a line's inclination relative to the horizontal. In analytic geometry, the slope of any line, ray, or line segment stands as the proportion of the vertical to the horizontal distance between any two points on it (“slope equals rise over run”).

Given

Slope

y = 4x-3

dy/dx = 4

slope =  4

intercepts y = 4(4) 3

y = 16-3

y = 13

To learn more about slope refer to:

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Answer:

30%

Step-by-step explanation:

you just add 10% and 20%

Hope it helps c:

Zelina scored 32% higher on the third quiz than on her first quiz.

The Percentage is defined as representing any number with respect to 100. It is denoted by the sign %.

Given that:-

From the given data we will see that:-

1 ) Zelina scored 10% higher on her second quiz than on her first quiz.

SQ = 1.10 FQ

2 ) On her third quiz, Zelina scored 20% higher than on her second quiz

TQ = 1.20SQ

From the above to expression solve for the first quiz:-

TQ = 1.20 x  1.10 FQ

TQ = 1.32FQ

Therefore Zelina scored 32% higher on the third quiz than on her first quiz.

To know more about percentages follow

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Answer:

3x³+3x²+3x+8+[tex]\frac{4}{x-1}[/tex]

Step-by-step explanation:

You can use synthetic division for this problem since the divisor is in (x-a) form. The fraction is the remainder over the divisor.

Answer:

1.944 ;

0.026

Step-by-step explanation:

Given :

Sample size, n = 34

Sample mean, xbar = 15

Population standard deviation, σ = 3

The hypothesis :

H0: μ ≤ 14

H1: μ > 14

The test statistic :

Test statistic = (xbar - μ) ÷ (σ/√(n))

Test statistic = (15 - 14) ÷ (3/√(34))

Test statistic = 1 / 0.5144957

Test statistic, Z = 1.944

The Pvalue :

Using the Pvalue from test statistic value :

Pvalue(1.944) = 0.026

Pvalue < α ; Reject H0

Answer:

24

Step-by-step explanation:

The number of rows (x) should b equal to the number of columns (x).

x²=576

x=√576 taking the square root of the product

x=24

Answer:

ON = KJ

Step-by-step explanation:

JKL = NOP

We know the angles match

<J = <N

<K = <O

< L = <P

And we know

JK = NO

KL =  OP

JL = NP

We are looking for ON = KJ

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Answer:

  (d)  KJ

Step-by-step explanation:

The segment of interest is named using the 2nd and 1st letters of the right side of the similarity statement.

The corresponding segment will be named using the 2nd and 1st letters of the left side of the similarity statement: KJ.

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Answer:

  (b)  BC = B"C"/3

Step-by-step explanation:

Choices A, C, D are all different ways of expressing the same relationship, and they are all incorrect.

B"C" is segment BC after dilation by a factor of 3, so it is 3 times as long as BC. That is, BC is 1/3 the length of B"C", choice B.

Answer:

I believe it's A

Step-by-step explanation:

I'm not sure sorry if its wrong

(B)

Step-by-step explanation:

Rewrite the equations into their standard forms. The first one can be rewritten as

[tex]10x - 12y = -5[/tex]

and the 2nd can be rewritten as

[tex]3x + 5y = -1[/tex]

Solving this system either by substitution or elimination, we get

[tex]x = -\dfrac{37}{86}\:\:\text{and}\:\:y= \dfrac{25}{86}[/tex]

If you add x + y, you'll get a negative number.

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Answer:

  B. x + y < 0

Step-by-step explanation:

The two equations can be cleared of fractions by multiplying by 15.

  15(2/3(x +1) -4/5y) = 15(1/3)

  10(x +1) -12y = 5

  10x -12y = -5

and

  15(2/5x +1/3(2y +1)) = 15(1/5)

  6x +5(2y +1) = 3

  6x +10y = -2

  3x +5y = -1 . . . . . eliminate common factor of 2

__

You can find the solutions any way you like, but you can answer the question without doing that. The lines are not parallel, nor coincident, so there is exactly one solution. (choices C and D are incorrect)

If we can locate the solution relative to the line x + y = 0, we can tell if choice A or choice B is correct. A quick look at the intercepts of the equations tells us the solution cannot lie in quadrants 1 or 4. The negative y-intercept and shallow slope (-3/5) of the second equation tells us the solution must lie below the line x + y = 0. That means x+y < 0, choice B.

_____

In the attached graph, the line x+y=0 is dashed orange. Above that line, x+y>0; below that line, x+y<0. We see the intersection point of the red and blue lines is in the region where x+y < 0.

For standard form equation ax+by = c, the x- and y-intercepts are c/a and c/b, respectively, so are easy to find from that form. Knowing these makes it easy to make a sketch of the graph, locating the solution point relative to the line x+y = 0.

Answer:

80 cm^2

Step-by-step explanation:

Let the width of the rectangle equal x. This means the length is x + 2, as it is 2 cm longer than the width. The formula for perimeter is: P = 2l + 2w, and substitute in the values of the length, width, and perimeter:

P = 2l + 2w

36 = 2(x + 2) + 2(x)

36 = 2x + 4 + 2x

36 = 4x + 4

4x = 32

x = 8

x represents the width, so the width is 8 and the length is 10. Area is length times width, so the area is 8 x 10 or 80 cm^2.

Step-by-step explanation:

let x be the width

p=2l+2w

36=2(2)+2(x)

36=4+2x

36-4=2x

32/2=2x/2(simplify)

x=16

therefore the width is 16cm

area of the rectangle is l×w

=2×16

=32cm"

therefore the area is 32cm"

Answer:

Step-by-step explanation:

slope of line through (6,-1) and (11,2) = (-1 - 2)/(6 - 11) = 3/5

slope of line through (5,-7) and (8,-2) = (-7 - (-2))/(8 - 5) = -5/3

product of the slopes = -1, so the lines are perpendicular.

Answer:

0.19

Step-by-step explanation:

Jane bought a shoe for 54.82 euros

She gave the store owner 55 euros

= 55-54.82

= 0.18 euros to franc

= 0.18× 1.08222

= 0.19 franc

Answer:

Each triangle is a right triangle.

Step-by-step explanation:

You can see each one has one 90 degree corner.

Answer:

13. True

14. True

15. False

Step-by-step explanation:

By using the Pythagorean Theorem a^2+b^2=c^2, you can evaluate whether or not the triangles are right triangles.

13. 8^2+15^2=17^2   ->  64+225=289  -> TRUE

14. 50^2+120^2=130^2  -> 2500+14400=16900  -> TRUE

15. 12^2+35^2=36^2  -> 144+1225 =/=1296 -> FALSE

Answer:

x=9

Step-by-step explanation:

[tex]\sqrt{x}[/tex]=3

[tex]\sqrt{x}[/tex]^2=3^2

x=9

Answer:

7 1/2

Step-by-step explanation:

2 1/2 ÷ 1/3

Change to an improper fraction

(2*1+2)/2 ÷ 1/3

5/2 ÷1/3

Copy dot flip

5/2 * 3/1

15/2

Change to a mixed number

7 1/2