Find the point on the parabola y^2 = 4x that is closest to the point (2, 8).

Answers

Answer 1

Answer:

(4, 4)

Step-by-step explanation:

There are a couple of ways to go at this:

Write an expression for the distance from a point on the parabola to the given point, then differentiate that and set the derivative to zero.Find the equation of a normal line to the parabola that goes through the given point.

1. The distance formula tells us for some point (x, y) on the parabola, the distance d satisfies ...

... d² = (x -2)² +(y -8)² . . . . . . . the y in this equation is a function of x

Differentiating with respect to x and setting dd/dx=0, we have ...

... 2d(dd/dx) = 0 = 2(x -2) +2(y -8)(dy/dx)

We can factor 2 from this to get

... 0 = x -2 +(y -8)(dy/dx)

Differentiating the parabola's equation, we find ...

... 2y(dy/dx) = 4

... dy/dx = 2/y

Substituting for x (=y²/4) and dy/dx into our derivative equation above, we get

... 0 = y²/4 -2 +(y -8)(2/y) = y²/4 -16/y

... 64 = y³ . . . . . . multiply by 4y, add 64

... 4 = y . . . . . . . . cube root

... y²/4 = 16/4 = x = 4

_____

2. The derivative above tells us the slope at point (x, y) on the parabola is ...

... dy/dx = 2/y

Then the slope of the normal line at that point is ...

... -1/(dy/dx) = -y/2

The normal line through the point (2, 8) will have equation (in point-slope form) ...

... y - 8 = (-y/2)(x -2)

Substituting for x using the equation of the parabola, we get

... y - 8 = (-y/2)(y²/4 -2)

Multiplying by 8 gives ...

... 8y -64 = -y³ +8y

... y³ = 64 . . . . subtract 8y, multiply by -1

... y = 4 . . . . . . cube root

... x = y²/4 = 4

The point on the parabola that is closest to the point (2, 8) is (4, 4).


Related Questions

-20,480 , -5,120 , -1280 , -320 what goes next

Answers

- 80, -20 and so on
- 1280/4 = -320
- 320/4 = - 80

Line IJ has an equation of a line y = −3x − 8. Which of the following could be an equation for a line that is parallel to line IJ?

A) y=3x+7
B) y=1/3x+7
C) y= -3x+7
D) y= -1/3x+7

Answers

Answer:

C) y = -3x +7

Step-by-step explanation:

It's all about recognizing patterns.

The form of the equation is ...

... y = mx + b

In this form, the coefficient of x, which we called "m" in the above, is the slope of the line. When two lines have the same slope, they are parallel. So, we're looking for an equation that has an x-coefficient of -3, the same as in the given equation.

The coefficient of x in selection C is -3, so that is our answer choice.

... C) y = -3x +7

Answer:

y = -3x +7 which is option C

got it right on my test.

Mark earns $135 for selling a $1500 refrigerator. Which sale listed has the same commission rate? $36 commission on a $400 dryer or B) $40 commission on a $500 dryer sale C) $210 commission on $1400 oven sale d) $30 commission on a $600 freezer sale?
salelisted has the same commssion rate. ?

Answers

The answer is A

36/400 * 3.8 = 136.6/1520
40/500 * 3 = 120/1500
210/1400 (not even close)
30/600 * 3 = 90/1800 (not even close)

so the two answer choices that are close are A and B, A has the closest numbers to the original commission rate.

Answer:

Option A is the correct choice.

Step-by-step explanation:

We have been given that Mark earns $135 for selling a $1500 refrigerator.

Since proportions states that two fractions are equal , so we will use proportions to find the same commission rate with the listed price from our given choices.

We can set proportion for commission and listed price as:

[tex]\frac{\text{Commission}}{\text{Listed price}}=\frac{135}{1500}[/tex]

Let us compare our given choices one by one.

A. $36 commission on a $400 dryer.

[tex]\frac{36}{400}=\frac{135}{1500}[/tex]

Upon simplifying our proportion we will get,

[tex]\frac{9}{100}=\frac{9}{100}[/tex]

[tex]0.09=0.09[/tex]

We can see that commission rates for both items are equal, therefore, option A is the correct choice.

B. $40 commission on a $500 dryer sale.

[tex]\frac{40}{500}=\frac{135}{1500}[/tex]

Upon simplifying our proportion we will get,

[tex]\frac{2}{25}=\frac{9}{100}[/tex]

[tex]0.08\neq 0.09[/tex]

We can see that both commission rates are different, therefore, option B is not a correct choice.

C. $210 commission on $1400 oven sale.

[tex]\frac{210}{1400}=\frac{135}{1500}[/tex]

Upon simplifying our proportion we will get,

[tex]\frac{3}{20}=\frac{9}{100}[/tex]

[tex]0.15\neq 0.09[/tex]  

Since the commission rates are different, therefore, option C is not a correct choice.

D.  $30 commission on a $600 freezer sale.

[tex]\frac{30}{1400}=\frac{135}{1500}[/tex]

Upon simplifying our proportion we will get,

[tex]\frac{3}{140}=\frac{9}{100}[/tex]

[tex]0.0214\neq 0.09[/tex]  

Since the commission rates are different, therefore, option D is not a correct choice.

A person made an estimate for a three–minute interval. the estimate was 241.5 seconds. what was the error of this estimate?

Answers

We know a minute is 60 seconds.  So 3 minutes would be 60X3=180.  4 minutes would be 60X4=240.  The error was the person rounded to 4 minutes instead of 3 minutes.

At an automobile factory, 1849 parts are made in 4 hours. What is the average rate at which parts are made per hour?

Answers

Just divide "1849 parts" by "4 hours:"  the average rate is 1849/4 parts/hour,

or 1849 parts/ 4 hours, or 462.25 parts/hour, or (rounded off) 462 parts/hour.

Answer:

462.25

Step-by-step explanation:

At an automobile factory, the number of parts are made in 4 hours = 1849.

We have to calculate the average rate of production per hour.

We will divide the production of parts in 4 hours by 4 to get the number of parts made per hour.

The average rate of production in one hour = [tex]\frac{1849}{4}[/tex]

                                                                         = 462.25/hour

462.25 parts are made per hour.

A seafood company sold 9,125 pounds of fish last month. If 6 seafood companies sold the same amount of fish, how much fish did the 6 companies sell last month in all ?

Answers

The 6 seafood companies sold 54,750 pounds of fish

What are 2 ways three people can share fifths?

Answers

if you have 5 pieces of something you split it up into 2 for each and then slip the last one into two.

Final answer:

Three people can share fifths by dividing one pie into five slices and each taking three, or dividing three pies into fifteen slices and each person getting one slice from each pie. Both methods ensure each person receives three-fifths of a pie.

Explanation:

Two ways that three people can share fifths involve division and allocation of pie (or any other divisible whole). One way is to take a single pie, divide it into five equal slices, and each person takes three slices. However, since we need to divide these among three people and a pie has only five slices, we'll end up with a fraction of a slice per person. The second way is to start with three pies, divide them so that there are a total of fifteen slices (five slices per pie), and then each person gets one slice from each pie, totaling three slices per person.

Here are two arithmetic representations of the scenarios:

First method: (3 slices/person) / 5 slices = 3/5 per personSecond method: 1 slice from each of 3 pies / 5 slices per pie = 3/5 per person

Whether we are dealing with one pie or three, each person ends up with the same fraction of the total available pie: three-fifths.

208,000,478 in expanded form

Answers

200,000,000+8,000,000+400+70+8

Alice leaves her house and walks to school. She walks 45 meters south and 336 meters east. How far is Alice from her house?

Answers

she is 381 meters away from her house
The way to figure this out is to first set it up on an x/y graph. it also looks like a compass, which tells you which direction east and south is. So first draw a point where 45 would be (also south). Now draw a point around 336 east. You are now going to use the Pythagorean Theorem (Asquared +Bsquared =Csquared) to figure it out. 336 squared, + 45 squared. When you get that answer, square it, giving you your distance. Answer = 339

How is adding 4.56 + 2.31 similar to adding $2.31 + $4.56?

Answers

They're all whole/natural numbers. The only difference is that one problem is in the form of currency. Anyhoo, you'll end up with the same answer. Currency, and an equation. The similarities are the factors, and the operations are the same.

Chris answered 61/66 questions correctly. What is his test average to the nearest thousandth?

Answers

61/66=x/100
x=61*100/66=92.424

kalen's truck has a 60 gallon fuel tank The fuel gauge points to 1/4 how much fuel does he need to buy to fill the tank show Your work

Answers

He should need 45 more gallons. 60/4=15 15gallons for every 1/4 of the tank. 60-15=45

what is the sum of (1-5q)+2(2.5q+8)

Answers

Answer:

17

Step-by-step explanation:

Eliminating parentheses, we have ...

... 1 - 5q +2·2.5q +2·8

... = 1 -5q +5q +16 . . . . . carry out the multiplication

... = q(-5+5) +(1 +16) . . . . group like terms

... = q·0 +17 . . . . . . . . . . . combine like terms

... = 17

put these in order from the smallest
6² 3 to the power of 4 2 to the power of 5 5³

Answers

Hello!

A = 6 to the power of 2, which is 36
B = 3 to the power of 4, which is 81
C = 2 to the power of 5, which is 32
D = 5 to the power of 3, which is 125

Therefore, the order is C, A, B, D

Hope that helped!
Helloo.

From least to greatest.
1. 6^2= 36
2. 3^4 = 81
3. 5^3 = 125
4. 2^5 = 128

What is the value of x?

Answers

The value of x is 35°

differentiate please..

y= √x +6 ÷ √x-6

Answers

[tex]\bf y=\cfrac{\sqrt{x}+6}{\sqrt{x}-6}\implies \cfrac{dy}{dx}=\stackrel{quotient~rule}{\cfrac{\frac{1}{2}x^{-\frac{1}{2}}(\sqrt{x-6})~~-~~(\sqrt{x}+6)\frac{1}{2}x^{-\frac{1}{2}}}{(\sqrt{x}-6)^2}}[/tex]

[tex]\bf \cfrac{dy}{dx}=\cfrac{\frac{1}{2}x^{-\frac{1}{2}}~(\underline{\sqrt{x}}-6~-~\underline{\sqrt{x}}-6)}{(\sqrt{x}-6)^2}\implies \cfrac{dy}{dx}=\cfrac{\frac{1}{2}x^{-\frac{1}{2}}(-12)}{(\sqrt{x}-6)^2} \\\\\\ \cfrac{dy}{dx}=\cfrac{\frac{-12}{2\sqrt{x}}}{(\sqrt{x}-6)^2}\implies \cfrac{dy}{dx}=\cfrac{\frac{-6}{\sqrt{x}}}{(\sqrt{x}-6)^2}\implies \cfrac{dy}{dx}=\cfrac{-6}{\sqrt{x}(\sqrt{x}-6)^2}[/tex]

Find the integer a such that
a.a ≡ 43 (mod 23) and −22 ≤ a ≤ 0.

Answers

The integer a such that a ≡ 43 (mod 23) and −22 ≤ a ≤ 0 is -3. A zero, a positive natural number, or a negative integer with a minus sign is an integer.

What do we mean when we say that integers are congruent to modulo?When two positive integers a and b are divided by a positive integer n, they are said to be congruent modulo n (or an is congruent to b modulo n), or if a b is divisible by n. It can be expressed as a b mod n, where n is the modulus.If n is a positive integer, then the integers a and b are said to be congruent modulo n, as denoted by the expression a b (modn).Division algorithm Allow dd and aa to be both positive integers. Following that, there are two distinct integers, qq and rr, where rd0 and rd are equal, resulting in a = dq + ra = dq + r

Therefore,

-3 is in between -22 and 0 so a =-3

a ≡ 43 (mod 23) and −22 ≤ a ≤ 0.

a ≡ 43 (mod 23)

≡ 43-22 (mod 23)

Simplifying,

≡ 20 (mod 23)

≡ 20-23 (mod 23)

Then we get,

≡ -3 (mod 23)

-3 is in between -22 and 0 so a =-3

To learn more about congruent modulo refer to:

brainly.com/question/13427492

#SPJ2

A)- -17
B)- -8
C)- -2
D)- 2
E)- 5
F)- 8
G)- 15
SELECT ALL THAT APPLY

Answers

B -8
D -2
G 15

That can represent an function that sentences

One canned juice drink is 25% orange juice; another is 10% orange juice. How many liters of each should be mixed together in order to get 15L that is 17% orange juice

Answers

let's say we use "x" of the 25% OJ... ok... well, how much juice is really in that "x" liters?  well, 25% of it is OJ, the rest is water, how much is 25% of x? well, (25/100) * x,  or 0.25x.

likewise, we'll use "y" of the 10% OJ, and it will end up with (10/100) *y or 0.10y of juice in it.

whatever "x" and "y" are, they must add up to 15 Liters, and the juice concentration on that mixture, must also be the sum of their sum concentration.

[tex]\bf \begin{array}{lccclll} &\stackrel{liters}{amount}&\stackrel{juice~\%}{quantity}&\stackrel{juice}{quantity}\\ &------&------&------\\ \textit{25\% juice}&x&0.25&0.25x\\ \textit{10\% juice}&y&0.10&0.10y\\ ------&------&------&------\\ mixture&15&0.17&2.55 \end{array} \\\\\\ \begin{cases} x+y=15\implies \boxed{y}=15-x\\ 0.25x+0.10y=2.55\\ ----------\\ 0.25x+0.10\left(\boxed{15-x} \right)=2.55 \end{cases} \\\\\\ 0.25x-0.10x+1.5=2.55\implies 0.15x=1.05\implies x=\cfrac{1.05}{0.15} \\\\\\ x=7[/tex]

how much will be it of the 10% juice?  well, y = 15 - x.

Jemma has 24 balls. Out of the 24 balls,
12 are yellow, 4 are pink, and the rest
are red. What is the ratio of the number
of red balls to the number of balls that
are either yellow or pink?

Answers

The ratio of red balls to either yellow or pink balls is 8:24, or simplified to the max it would be 1:3

Billy wants to live in the area defined by y < 3x − 6. Explain how you can identify the houses in which Billy is interested in living. (2 points)

Answers

check the picture below.

to graph an inequality, you pretty much first off, need to graph the "equality" or equation, so for y < 3x − 6, first off, graph the line y = 3x − 6.

and then you do a "true" or "false" check.

now, if you look at the line below, it splits the grid in two sections, so, let's check a point in either section, if one is false, the other is true and the other way around.

so, let's check the region on the left-hand-side, hmmmm say point 0,0, the origin.

y < 3x - 6

y = 0,  x = 0  thus

0 < 3(0) - 6

0 < -6   <--- now, is that really true? is 0 lesser than -6? not quite, is false.

recall that on the negative side, the closer to 0, the larger the value, so -1 is much larger than -1,000,000.

because the point 0,0 yielded a false inequality, that region is the "false region" and thus not shaded, therefore, the other side must be the "true region", and thus we shade that then.

we can run a quick check on that btw, say on point 4,4

y =4,   x = 4  thus

4 < 3(4) - 6

4 < 12 - 6

4 < 8    <---- yeap, is true, 4 is lesser/smaller than 8.

hmm ohh yes, the line needs to be dashed for a < or >, because it "has that boundary but it does not include it", unlike ⩽ and ⩾, which is a solid line, because it has that boundary and it includes it too.

Sam opened a savings account with an initial deposit of $2,000. Since then, he has never made any other deposits or withdrawals. His savings account earns 0.4% interest monthly and an annual bonus of 1.5% interest. Which equation gives the approximate amount, A(x), he has in his savings account as a function of x, the number of years since his initial deposit?


A(x) ≈ 2,000 + (1.059)x3

A(x) ≈ 2,000(1.019)x2

A(x) ≈ 2,000(1.065)x

A(x) ≈ 2,000(1.059)x2

Answers

Answer:

Third option:

[tex]A(x)\approx 2,000(1.065)^x[/tex]

Step-by-step explanation:

Notice if we invest 2,000 then the first month then after the first 0.4% interest is earned we will have in the account:

2,000(1+0.004) = 2,000(1.004)

I just applied the simple interest formula.

Then after the second month we will have:

[tex]2,000(1.004)(1.004) = 2,000(1.004)^2[/tex]

And so on each month.

So at the end of the first year (12 months) we have:

[tex]2,000(1.004)^{12}[/tex]

But we also earn an additional 1.5% in the year, so we will have:

[tex]2,000(1.004)^{12}(1.015)[/tex]

At the end of the second year we will have:

[tex]2,000[(1.004)^{12}(1.015)]^2[/tex]

At the end of the third year:

[tex]2,000[(1.004)^{12}(1.015)]^2[/tex]

And so on,

So if the number of years is denoted with x, at the end of x years we will have the following amount in the savings:

[tex]2,000[(1.004)^{12}(1.015)]^x[/tex]

We use our calculator to simplify that inside the brackets:

[tex](1.004)^{12}(1.015)=1.06481[/tex]

Rounding  to the third decimal place we get: 1.065

So notice the amount in the savings after x years will be:

[tex]2,000(1.065)^x[/tex]

Since they want it in function notation we just write the A(x) that denotes the amount in the savings:

[tex]A(x)\approx 2,000(1.065)^x[/tex]

A scatterplot is produced to compare the size of a lake to the number of fish that are in it. There are 15 data points, each representing a different lake. The points are widely dispersed on the scatterplot with no pattern of grouping. Interpret what the results of the scatterplot tell you about the relationship between the two variables.

Answers

A: Since there is no cluster formed in the scatterplot, the two variables are not related. Therefore, based on the data shown in the scatterplot, the number of fish in a lake is not dependent on the size of the lake.

Based on the dispersion of the scatterplot, we can infer that there is no relationship between the variables.

Relationships in scatterplots Data points are used to predict relationships. If a line can be drawn based on these data points, then a relationship exists.

The fact that these data points are dispersed however and offer no form of grouping, means that the variables are not related and show no correlational trend.

Find out more on scatterplots at https://brainly.com/question/2749543.

Emma uses 5 ounces of milk to make a shake.she want to buy enough milk to make 7 shake and she want to buy the smallest size container ok milk that she can.should she buy a pint a quart or gallon of milk?justify your answer Help

Answers

Pint gallon because for gallon it is 0.352 of a gallon

how many fossil kits with 10 samples each have the same number of fossils as 30 fossil kits with 8 samples each?

Answers

((( answer 24 )))as 30×8= 240 and 10×24 = 240

Answer:

24 fossil kits.

Step-by-step explanation:

Given,

The number of fossil kits = 30,

the number of samples each has  = 8,

So, the total samples = number of fossil kits × the number of samples contained by each kit

= 30 × 8

= 240,

Let x be the number fossil kits with 10 samples each,

Total samples = 10x

According to the question,

10x = 240

[tex]\implies x =\frac{240}{10}=24[/tex]

Hence, there would be 24 fossil kits with 10 samples each.

Which ordered pairs are solutions to the inequality y−4x≥−5 ?

Select each correct answer.



(−2, 1)

(−4, 2)

(4, 0)

(5, −2)

(1, −1)

Answers

The given inequality is
y - 4x ≥ - 5

To find the correct answer, we should test each answer as shown below.
Test (-2. 1): 
y - 4x = 1 - 4(-2) = 9
It is ≥ -5.
CORRECT

Test (-4, 2)
y - 4x = 2 - 4(-4) = 18
It is ≥ -5
CORRECT

Test (4,0)
y - 4x = 0 - 4(4) = -16
It is < -5
INCORRECT

Test (5,-2)
y - 4x = -2 - 4(5) = -22
It is < -5
INCORRECT

Test (1,-1)
y - 4x = -1 - 4(1) = -5
It is ≥ -5.
CORRECT

Answer: The correct answers are
(-2,1)
(-4,2)
(1,-1)

Answer:

The correct answers are

(-2,1)

(-4,2)

(1,-1)

Step-by-step explanation:

hope dis help u guys, habe a good rest of ya day!

write the equation of the line MN, which is formed by the points M(-3,5) and N(2,0)

Answers

The equation is y = -x + 2

Step 1

Find the slope of the given line

Let

[tex]M(-3,5)\ N(2,0)[/tex]

we know that

the slope between two points is equal to

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

substitute the values

[tex]m=\frac{0-5}{2+3}[/tex]

[tex]m=\frac{-5}{5}[/tex]

[tex]m=-1[/tex]

Step 2

Find the equation of the line

we know that

the equation of the line into point-slope form is equal to

[tex]y-y1=m(x-x1)[/tex]

we have  

[tex]m=-1[/tex]

point N [tex](2,0)[/tex]

substitute the values

[tex]y-0=-1(x-2)[/tex]

[tex]y=-x+2[/tex]

therefore

the answer is

[tex]y=-x+2[/tex]

write a word problem that can be solved by ordering three decimals to thousandths.

Answers

Angelo wants to grow the smallest pea which will be 2.6 times smaller than worlds smallest pea currently is 5 millimeters , what is 5 divided by 2.6? Given: smallest pea = 2.6 millimeters, worlds smallest pea = 5 millimeters

[Solution: 5 / 2.6 = 1.923076923076923 millimeters or approximately 1.923 millimeters]

What produces a graph in a straight line

Answers

Linear equations in one variables shows always graph in straight line,

For ex: x = 3, y = 4, x = -1.5, y = -2/3

Also two variables linear equations with degree of 0 or 1 (Each term) shows always graph in straight line,

For ex: x + y = 5, 2x - 4y = 7 etc.

Select all numbers that are irrational. 1049−−√ 3.14 π 0.5

Answers

The answer would be 10/49 and π which are irrational numbers from the definition of the irrational number.

What is an irrational number?

It is defined as the numbers in all real numbers which cannot be represented as rational numbers, in other words, the irrational number cannot be expressed in the form of p/q form.

A rational number is a sort of real number that has the form p/q and does not equal zero.

It is given that:

The numbers are:

10/49,  3.14,  π,  0.5

As we know, from the definition of the irrational, the numbers which cannot be represented as rational numbers, in other words, the irrational number cannot be expressed in the form of p/q form.

The numbers 10/49 and π are irrational numbers.

Thus, the answer would be 10/49 and π which are irrational numbers from the definition of the irrational number.

Learn more about the irrational number here:

brainly.com/question/17450097

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