What is the explicit formula for this sequence?

What Is The Explicit Formula For This Sequence?

Answers

Answer 1

Greetings from Brasil...

With the recursive formula, lets build the sequence:

A1 = 4

A2 = A1 - 7

A3 = A2 - 7

A4 = A3 - 7

A5 = A4 - 7

(...)

But pay attention to A3....

A3 = A2 - 7   but  A2 = A1 - 7 , so rewriting A3

A3 = (A1 - 7) - 7 ⇒ A3 = A1 + 2.(- 7)

A4 = A3 - 7 ⇒ A4 = [(A1 - 7) - 7] - 7 = A1 + 3.(- 7)

A5 =  {[(A1 - 7) - 7] - 7} - 7 = A5 + 4.(- 7)  

so

An = A1 + (n - 1).(- 7)


Related Questions

g(x)=5-2x what is domain ​

Answers

Answer:

  all real numbers

Step-by-step explanation:

The domain of any polynomial function is "all real numbers."

A diabetes drug cost $78 online. This cost is 75% of the cost of the
prescription in the store. How much is the prescription in the store?

plss help​

Answers

Answer:

$104

Step-by-step explanation:

If the cost in the store is x we can write:

75%x = 78

0.75x = 78

x = 78 / 0.75 = 104

Answer:

$104 in the store

Step-by-step explanation:

To find the original cost before the discount, you divide the discounted price by the percentage, getting 104.

Find the angle θ between the two sides of a triangle whose lengths are 5cm and 4cm , if its area is 5cm²

Answers

[tex] \Delta = \frac 1 2 a b \sin C[/tex]

[tex]\Delta=5, \quad a=5, \quad b=4[/tex]

[tex]\sin C = \dfrac{2 \Delta}{ab} = \dfrac{2 (5)}{5(4) } = \dfrac 1 2[/tex]

[tex]C=30^\circ \textrm{ or } C=150^\circ[/tex]

Answer: two possibilities, θ=30° or 150°

Jen plans to tile the kitchen floor. Each time covers 3 square meters. The kitchen is 4 5/6 meters wide and 5 meters long. How many times does Jen need to cover the kitchen floor?

Answers

Answer:

Jen needs approximately 8 tiles to cover the kitchen floor

Step-by-step explanation:

What we want to calculate here is the number of tiles needed to cover the kitchen floor.

The first thing we need to do here is to calculate the area of the kitchen floor.

Mathematically, that would be the product of the length of the kitchen floor and the length of the width.

That is; 4 5/6 * 5 = 29/6 * 5 = 145/6 m^2

Now, to calculate the number of tiles needed, we only need to divide the area of the kitchen floor by the area of the individual tiles

Mathematically, that would be;

145/6 ÷ 3 = 145/6 * 1/3 = 145/18 = 8.05556

This is approximately 8 tiles

if the pattern continued,what value of y would be associated with x=6? y=​

Answers

Answer: the answer would be 24

Step-by-step explanation: just did the assignment

Answer:

24

Step-by-step explanation:

Just got it right on edge 2020

What is the mode for this set of data? 5,6,13,2,6,11,6,5,3,14

Answers

Answer:

6

Step-by-step explanation:

6 appears the most

Answer:

6

Step-by-step explanation:

Put the data in order from smallest to largest

5,6,13,2,6,11,6,5,3,14

2,3,5,5,6,6,6,11,13,14

The mode is the number that appears most often

6 appears most often so it is the mode

|3x+9|= 30

Answer: x=7, -13

Answers

Answer:

[tex]\boxed{x=7, \: x=-13}[/tex]

Step-by-step explanation:

[tex]|3x+9|= 30[/tex]

Solve for absolute value.

There are two possibilities.

One possibility:

[tex]3x+9=30\\3x=21\\x=7[/tex]

Second possibility:

[tex]3x+9=-30\\3x=-39\\x=-13[/tex]

Jordan and his bro got 100 dollar to divied up. If 1/3 of the money jordon got was the same as 1/2 the money his bro got how much money did his bro get

Answers

Answer:

Jordon's brother got $40

Step-by-step explanation:

We can set up a system of equations to solve this.

Let's say that Jordon got x dollars.

His brother got y dollars.

x+y=100 since they are dividing the 100 dollars

1/3x=1/2y (the same indicates that they are equal)

Multiply the entire second equation by 3.

x=1.5y

Now we can substitute 1.5y in for x in the first equation.

x+y=100

1.5y+y=100

2.5y=100

Divide both sides by 2.5

y=40

Jordon's brother got $40.

Plug that in to find how much Jordon got.

x+y=100

x+40=100

Subtract 40 from both sides

x=60

Jordon got 60.

A lead ball weighs 326 grams. Find the radius of the ball to the nearest tenth of a
centimeter.

Answers

Answer:

1.9cm

Step-by-step explanation:

The density d of a material is related to its mass m and volume V as follows;

d = [tex]\frac{m}{V}[/tex]             ------------------(i)

The material in question here is the lead ball.

Now, from known experiment;

the density of lead is 11.34g/cm³

From the question, the weight/mass of the lead ball is 326g

Substitute these values into equation (i) as follows;

11.34 = [tex]\frac{326}{V}[/tex]

V = [tex]\frac{326}{11.34}[/tex]

V = 28.75cm³

Now, since the ball is of course spherical, we can get the radius by using the following relation from the volume of a sphere;

V = [tex]\frac{4}{3} \pi r^3[/tex]          [V = volume, r = radius]

V = 28.75cm³

=> 28.75 = [tex]\frac{4}{3} \pi r^3[/tex]

=> 3 x 28.75 = 4 π r³

=> 86.25 = 4 π r³

=> 21.5625 = π r³      [Take π = 3.142]

=> 21.5625 = (3.142) r³      [divide both sides by 3.142]

=> 6.86 = r³              [Take the cube root of both sides]

=> ∛6.86 = ∛r³

=> 1.90 = r

Therefore, the radius is 1.9cm to the nearest tenth

Fred Salmon purchased six $1,000 bonds at 92. The bonds pay 6.5%.
7
What was the cost of the bonds?
What was the total annual interest?
What is the yield?

Answers

Answer:

if he bought 6 bonds at $1,000 each, then 6*1000

Step-by-step explanation:

if the interest is 6.5%, then the annual interst is also 6.5%

Answer:

6.5% should be the answer of annual

PLEASE HELP ME TO COMPLETE THIS QUESTION ​

Answers

Answer:

Step-by-step explanation:

a) Increase in population =510,000 - 430,000 = 80,000

Percentage increase = [tex]\frac{80,000}{430,000}*100[/tex]

                                   = [tex]\frac{800}{43}[/tex]

                                   = 18.6 %

b) Percentage increase = 17.3%

Increase in population = 17.3% * 510,000

                                     = 0.173 * 510,000

                                     = 88,230

Predicted population in 2021 = 510,000 + 88,230

                                                 =  598,230

Find all values of x, giving your answer to 3 significant figures where necessary, for 0 is equal or smaller than x and 2 pi is equal or larger than x.

a) 3 sin x + 2tan x = 0​

Answers

Please is the day you you can go eat with me

JUST DO IT ALREADY!!! WILL MARK AS BRAINLIEST In a certain lottery, 3 balls are drawn (at random) from 10 white balls numbered from 1 to 10, and one special ball is drawn (at random) from ten red balls numbered from 11 to 20. When you buy a ticket, you choose three numbers from 1 to 10, and one number from 11 to 20. If the numbers on your ticket match at least two of the white balls or match the red SuperBall, then you win a super prize. What is the probability that you win a super prize? PUT THE CORRECT ANSWER IN ALREADY!!!!!

Answers

Answer:

4/30 is the answer the probability is 4/30

Solve for “x” to the nearest tenth. (Hint: Find a decimal that, when multiplied by itself, will be approximately 46.)

Answers

Answer:

6.79

Step-by-step explanation:

According to Question,

[tex] {x}^{2} = 46[/tex]

Squaring on both sides

[tex] \sqrt{ {x}^{2} } = \sqrt{46} [/tex]

Calculate

[tex]x = 6.79[/tex]

Let's check :

If we multiply 6.79 by itself, then the result will be approximately 46.

Hope this helps..

Best regards!!

what does it mean for a savings account to have a minimum balance

Answers

Step-by-step explanation:

You have to retain a certain amount of money

in that account forever. Say you need $50 to

start an account, you have $200 in that account.

You cannot take out more than $150 from that

account.

Answer:

A: If you do not keep at least that much money in the account, you will be assessed fees.

Step-by-step explanation:

As mountain climbers know, the higher you go, the cooler the temperature gets. At noon on July 4th last summer, the temperature at the top of Mt. Washington — elevation 6288 feet — was 56◦F. The temperature at base camp in Pinkham Notch — elevation 2041 feet — was 87◦F. It was a clear, still day. At that moment, a group of hikers reached Tuckerman Junction — elevation 5376 feet. To the nearest degree, calculate the temperature the hikers were experiencing at that time and place. When you decided how to model this situation, what assumptions did you make?

Answers

Answer:

a. 63 °F

b. When i decided to model the situation, I assumed that the temperature varied inversely as the elevation and that the change in elevation or temperature was linear.

Step-by-step explanation:

a. To model this situation, we assume the temperature varies inversely as elevation decreases since at elevation 6288 ft the temperature is 56 °F and at elevation 2041 ft, the temperature is 87 °F

So, we model this as a straight line.

Let m be the gradient of the line.

Let the (6288 ft, 56 F) represent a point on the line and (2041 ft, 87 °F) represent another point on the line.

So m = (6288 ft - 2041 ft)/(56 °F - 87 °F) = 4247 ft/-31 °F = -137 ft/°F

At elevation 5376 ft, let the temperature be T and (5376 ft, T) represent another point on the line.

Since it is a straight line, any of the other two points matched with this point should also give our gradient. Since in the gradient, we took the point (6288 ft, 56 °F) first, we will also take it first in this instant.

So m = -137 ft/ °F = (6288 ft - 5376 ft)/(56 °F - T)

-137 ft/°F = 912 ft/(56 °F - T)

(56 °F - T)/912 ft = -1/(137 ft/ °F)

56 °F - T = -912 ft/(137 ft/°F)

56 °F - T = 6.66 °F

T = 56 °F + 6.66 °F

T = 62.66 °F

T ≅ 62.7 °F

T ≅ 63 °F to the nearest degree

b. When i decided to model the situation, I assumed that the temperature varied inversely as the elevation and that the change in elevation or temperature was linear.

Write the equation of a hyperbola centered at the origin with x-intercepts +/- 4 and foci of +/-2(sqrt5)

Answers

Answer:

[tex]\frac{x^2}{16}-\frac{b^2}{4}=1[/tex]

Step-by-step explanation:

A hyperbola is the locus of a point such that its distance from a point to two points (known as foci) is a positive constant.

The standard equation of a hyperbola centered at the origin with transverse on the x axis is given as:

[tex]\frac{x^2}{a^2}-\frac{y^2}{b^2}=1[/tex]

The coordinates of the foci is at (±c, 0), where c² = a² + b²

Given that  a hyperbola centered at the origin with x-intercepts +/- 4 and foci of +/-2√5. Since the x intercept is ±4, this means that at y = 0, x = 4. Substituting in the standard equation:

[tex]\frac{x^2}{a^2}-\frac{y^2}{b^2}=1\\\frac{4^2}{a^2}-\frac{0}{b^2} =1\\\frac{4^2}{a^2}=1\\ a^2=16\\a=\sqrt{16}=4\\ a=4[/tex]

The foci c is at +/-2√5, using c² = a² + b²:

[tex]c^2=a^2+b^2\\(2\sqrt{5} )^2=4^2+b^2\\20 = 16 + b^2\\b^2=20-16\\b^2=4\\b=\sqrt{4}=2\\ b=2[/tex]

Substituting the value of a and b to get the equation of the hyperbola:

[tex]\frac{x^2}{a^2}-\frac{y^2}{b^2}=1\\\\\frac{x^2}{16}-\frac{b^2}{4}=1[/tex]

i need help im confused on how to do this. need correct answer ​

Answers

Answer:

11√6

Step-by-step explanation:

5√6 +6√6 will equal to 11√6, because since √6 is the same, you just add the number on the outside

In a scale drawing of a rectangular deck, the
length is 10 inches and the width is 8 inches. In
the drawing, 4 inches represents 3 yards. What
is the length of the actual deck, in yards?​

Answers

Answer:

45

Step-by-step explanation:

10/4x3=7.5

8/4x3=6

6x7.5=45yards

divide 0.377 ÷ 2.9 dosto please solve it​

Answers

answer: it should be 0.13 if i’m not mistaken
The answer should be 0.13

Examine the diagram of circle C. Points A, B, and Q are on circle C. Given that m∠ACB=52∘, what is the arc length of AQB⌢?

Answers

Hey there! :)

Answer:

Third choice: 13π/15 in.

Step-by-step explanation:

Begin by finding the circumference of the entire circle. Use the formula

C = 2rπ to solve:

C = 2(3)π

C = 6π.

Next, we can set up a proportion to find the arc length of AQB:

[tex]\frac{6\pi }{360}= \frac{x}{52}[/tex]

Cross multiply:

52 · 6π = 360 · x

312π = 360x

Divide both sides by 360:

312π/360 = 360x/360

x = 13π/15 in.

Answer:

The answer is 77n/15 inches :)

Step-by-step explanation:

An entertainment services provider on the internet has 10000 subscribers paying $15 per month. It can get 1000 more subscribers for each $1 decrease in the monthly fee. Determine the monthly fee that will yield the maximum monthly revenue and the value of that revenue

Answers

Answer:

Monthly fee that will yield the maximum monthly revenue is  $12.5

Then the value of the maximum monthly revenue is $156 250

Step-by-step explanation:

x   - value of decrease

1000x   - number of new subscribers for $x decrease

10000+1000x  - number of subscribers after $x decrease in the monthly fee

15-1x      the monthly fee after $x decrease

f(x) = (10000 + 1000x)(15 - x)           ← quadratic function

For quadratic function given in standard form:  f(x) =a(x-h)²+k  where a<0 the f(x)=k is the maximum value of function, and occurs for x=h

[tex]h=\frac{-b}{2a}\ ,\quad k=f(h)[/tex]

Expressing given function to standard form:

f(x) = 1000(10 + x)(15 - x)

f(x) = 1000(150 - 10x + 15x - x²)

f(x) = 1000(-x² + 5x + 150)

f(x) = -1000x² + 5000x + 150000                          {a=-1000<0}

[tex]h=\dfrac{-5000}{2\cdot(-1000)}=\dfrac{5000}{2000}=\dfrac52=2.5\\\\k=f(2.5)=1000(10+2.5)(15-2.5)=1000\cdot12.5\cdot12.5=156\,250[/tex]

15-2.5 = 12.5

Answer:

Monthly fee is $12.5

Value of revenue is $156,250

Find the length of an earthworm 4 hours after its birth

Answers

Answer:

Maximum is 14 inches so maybe 5 inches?

Step-by-step explanation:

Alexandria is practicing her long distance running. On day 0, she can run 2 miles without stopping. She wants to add 1/4 mile to her run each day.

What is the slope for this linear relationship?

Answers

Answer:

slope = 1/4

Step-by-step explanation:

If a equation is in form of y = mx + c

them m is the slope of line.

____________________________________________

Let Y(d) be the distance ran by Alexandria on dth day

Y(0) = 2

she adds 1/4 miles each day then

Y(1) = 2 + 1/4

Y(2) = 2 + 1/4 +1/4 = 2 +1/4(2)

Y(3) = 2 + 1/4 +1/4 +1/4= 2 +1/4(3)

.

.

.

.

similarly

in d days she can run 2 miles + 1/4*d miles

thus, we have

Y(d) = 2 + 1/4(d)

it can be also solved

Thus we see that it is a linear relationship y = 2 + 1/4(d)

which is in the form of y = mx + c

comparing mx to 1/4 d

we have m = 1/4

thus,

slope of this linear relationship is 1/4

Place
Is a city is in North America
India
Tokyo
Houston

Peru
New York
Tijuana


Canada

Let event A = The place is a city.
Let event B = The place is in North America.
What is P(A and B)?

Answers

Answer:

[tex]P(A\ and\ B) = \frac{3}{7}[/tex]

Step-by-step explanation:

Your question is not well presented; (See Attachment for complete details)

Required

Find P(A n B)

where

A = Event that the place is a city

B = Event that the place is in North

The first step is to get the sample space;

Let S represent the sample space;

[tex]S = \{India,\ Tokyo,\ Houston,\ Peru,\ New York,\ Tijuana,\ Canada \}[/tex]

[tex]n(S) = 7[/tex]

The next is to list events A and B

A = City

[tex]A = \{Tokyo,\ Houston,\ New York,\ Tijuana\}[/tex]

B = North America

[tex]B = \{Houston,\ New York,\ Tijuana,\ Canada\}[/tex]

The next is to list common elements in A and B

[tex]A\ n\ B = \{Houston,\ New York,\ Tijuana\}[/tex]

[tex]n(A\ and\ B) = 3[/tex]

The probability of A and B is calculated as follows;

[tex]P(A\ and\ B) = \frac{n(A\ and\ B)}{n(S)}[/tex]

Substitute [tex]n(A\ and\ B) = 3[/tex] and [tex]n(S) = 7[/tex] in the expression above

[tex]P(A\ and\ B) = \frac{3}{7}[/tex]

hi :) how to do the last part?

Answers

Answer: 1200

Step-by-step explanation:

as t → ∞, the e-value will get very very very small and be considered insignificant. In other words, as t → ∞, e → 0.

600(2 + 0) = 1200

Furthermore, if you graph this equation, you will see that the asymptote is: y = 1200. So, the y-value will get really close to 1200 but will never actually reach this value.

Which side lengths form a right triangle?

Answers

Answer:

B

Step-by-step explanation:

sqrt30 -6^2 doesn't work

2.5 sqrt18 and 5 do work

The number of a two dollar bill i need to pay for a purchase is 9 more than the number of 5 dollar bills i need to pay for the same purchase what is the cost of the purchase?

Answers

Answer:

$60

Step-by-step explanation:

Let's say we need t $2 bills and v $5 bills.

We need 9 more $2 bills than $5 bills, so:

t = 9 + v

We also know that the amount of money in t $2 bills is 2 * t = 2t. The amount of money in v + 9 $5 bills is 5 * (v + 9) = 5v + 45. These amounts are equal:

5v + 45 = 2t

Plug v + 9 in for t in 5v = 2t + 18:

5v = 2t + 18

5v = 2 * (9 + v) + 18

5v = 18 + 2v + 18

3v = 36

v = 12

We have 12 $5 bills, so that total cost is 12 * 5 = $60.

~ an aesthetics lover

Plz Which of these graphs represents a function?

Answers

Answer:

x.

Step-by-step explanation:

you know that x is a function because for one x-value there is only one possible y-value

Answer: X

Step-by-step explanation:

x because it doesn't fail the vertical line test

A company has determined that its weekly profit is a function of the number of items that it sells. Which equation could represent the weekly profit in thousands of dollars, y, when the company sells x items? y squared = 4 x squared minus 100 y = negative x squared + 50 x minus 300 x = negative y squared minus 400 x squared = negative 6 y squared + 200

Answers

Answer:

B. y= -x^2 + 50x - 300

Step-by-step explanation:

Options given

A. y^2=4x^2 - 100

B. y= -x^2 + 50x - 300

C. x= -y^2 - 400

D. x^2= -6y^2 + 200

We are to find profits (y) function in thousands of dollars if the company sells x items.

We will use elimination method to eliminate the wrong options above in order to find the correct answer

Option A. y^2= 4x^2 - 100 is used to find the square of the profit function

Option B. y= -x^2 + 50x - 300 is used to calculate profit (y) function

Option C. x= -y^2 - 400 is for the calculation of the items x sold

Option D. x^2= -6y^2 + 200 is to find items x sold squared.

Since, we are required to find the profit (y) function, option A, C and D will be eliminated.

We are left with option B which is the correct answer to the question.

The weekly profits (y) function in thousands of dollars when the company sells x items is

B. y= -x^2 + 50x - 300

Answer:

B.

Step-by-step explanation:

I just took the quiz on edge

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