Use sigma notation to represent the sum of the first seven terms of the following sequence: −4, −6, −8, …

Answers

Answer 1

Answer:

[tex]\sum_{n = 1}^{7} -2 -2n[/tex]

Step-by-step explanation:

Arithmetic sequence:

In an arithmetic sequence, the difference of consecutive terms is always the same, called common difference.

The nth term of a sequence is given by:

[tex]a_{n} = a_1 + (n-1)d[/tex]

In which [tex]a_1[/tex] is the first term and d is the common difference.

Sigma notation to represent the sum of the first seven terms

Sum going from the index starting at 1 and finishing at 7, that is:

[tex]\sum_{n = 1}^{7} f(n)[/tex]

Now we have to fund the function, which is given by an arithmetic sequence.

−4, −6, −8,

First term -4, common difference - 6 - (-4) = -6 + 4 = -2, so [tex]a_1 = -4, d = -2[/tex]

Then

[tex]f(n) = a_{n} = a_1 + (n-1)d[/tex]

[tex]f(n) = -4 + (n-1)(-2)[/tex]

[tex]f(n) = -4 - 2n + 2 = -2 - 2n[/tex]

Sigma notation:

Replacing f(n)

[tex]\sum_{n = 1}^{7} -2 -2n[/tex]


Related Questions

A car which was advertised for sale for 95000, was ultimately sold for 83600. Find the percent reduction in the price?

Answers

Answer: 12%

Step-by-step explanation:

95,000-83,600=11,400

(11,400/95000)(100) = 12%

The percentage reduction in the price of the car is 12%

What are percentages?

A percentage is a number or ratio that can be expressed as a fraction of 100. If we have to calculate the percent of a number, divide the number by the whole and multiply by 100. Hence, the percentage means, a part per hundred. The word percent means per 100. It is represented by the symbol “%”

Given here: Original price of car=95000 and Selling price=83600

Thus the reduction in price= 95000-83600

                                            =11400

Thus percentage reduction in the price of the car is

= 11400/95000 × 100

=12%

Hence, The percentage reduction in the price of the car is 12%

Learn more about percentages here:

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When f(x) =-3 what is x?

Answers

Answer:

D or -1

Step-by-step explanation:

It says that f(x) is equal to -3.

f(x) is the same as y-values, and x is the same as the x-values on a coordinate grid because x is the independent variable, meaning y is the dependent variable, where f(x) depends on the value of x to find y.

So if y is -3, it can be found on the graph on the 4th line, so x = -1 when y = -3

It’s D or -10 benefits hxh sqtcqovlvosuq shopvpousg

Which is a perfect square?
6’1
6’2
6’3
6’5

Answers

Answer:

6'2

Step-by-step explanation:

6’3 is the answer I believe



Let h(x)=20e^kx where k ɛ R (Picture attached. Thank you so much!)

Answers

Answer:

A)

[tex]k=0[/tex]

B)

[tex]\displaystyle \begin{aligned} 2k + 1& = 2\ln 20 + 1 \\ &\approx 2.3863\end{aligned}[/tex]

C)

[tex]\displaystyle \begin{aligned} k - 3&= \ln \frac{1}{2} - 3 \\ &\approx-3.6931 \end{aligned}[/tex]

Step-by-step explanation:

We are given the function:

[tex]\displaystyle h(x) = 20e^{kx} \text{ where } k \in \mathbb{R}[/tex]

A)

Given that h(1) = 20, we want to find k.

h(1) = 20 means that h(x) = 20 when x = 1. Substitute:

[tex]\displaystyle (20) = 20e^{k(1)}[/tex]

Simplify:

[tex]1= e^k[/tex]

Anything raised to zero (except for zero) is one. Therefore:

[tex]k=0[/tex]

B)

Given that h(1) = 40, we want to find 2k + 1.

Likewise, this means that h(x) = 40 when x = 1. Substitute:

[tex]\displaystyle (40) = 20e^{k(1)}[/tex]

Simplify:

[tex]\displaystyle 2 = e^{k}[/tex]

We can take the natural log of both sides:

[tex]\displaystyle \ln 2 = \underbrace{k\ln e}_{\ln a^b = b\ln a}[/tex]

By definition, ln(e) = 1. Hence:

[tex]\displaystyle k = \ln 2[/tex]

Therefore:

[tex]2k+1 = 2\ln 2+ 1 \approx 2.3863[/tex]

C)

Given that h(1) = 10, we want to find k - 3.

Again, this meas that h(x) = 10 when x = 1. Substitute:

[tex]\displaystyle (10) = 20e^{k(1)}[/tex]

Simplfy:

[tex]\displaystyle \frac{1}{2} = e^k[/tex]

Take the natural log of both sides:

[tex]\displaystyle \ln \frac{1}{2} = k\ln e[/tex]

Therefore:

[tex]\displaystyle k = \ln \frac{1}{2}[/tex]

Therefore:

[tex]\displaystyle k - 3 = \ln\frac{1}{2} - 3\approx-3.6931[/tex]

(7/8*9)*3/4*(9/3*5)=

Answers

Answer:

2835/32 or 88 19/32

Step-by-step explanation:

(7/8 × 9) × 3/4 × (9/3 × 5)= 63/8 × 3/4 × (3 × 5)= 63/8 × 3/4 × 15= 2835/32 or 88 19/32

[tex]\tt{ \green{P} \orange{s} \red{y} \blue{x} \pink{c} \purple{h} \green{i} e}[/tex]

Answer:

[tex]88 \frac{19}{32} [/tex]

Given: 3x+11=y, solve for x if y = 29

Answers

answer is 6

Step-by-step explanation:

3x+11=y

y=29

3x+11=29

3x=29-11

3x=18

x=18÷3

x=6

Answer:6

Step-by-step explanation:

3x+11=29

3x=29-11

3x=18

X=18/3

X=6

Tính tích phân sau bằng cách dùng tọa độ cực I=∫∫ [tex]\frac{1}{\sqrt{x^{2} +y^{2} } }[/tex]dxdy R là miền nằm trọg góc phần tư thứ nhất thỏa mãn 4[tex]\leq x^{2} +y^{2} \leq 9[/tex]

Answers

It sounds like R is the region (in polar coordinates)

R = {(r, θ) : 2 ≤ r ≤ 3 and 0 ≤ θ ≤ π/2}

Then the integral is

[tex]\displaystyle \iint_R\frac{\mathrm dx\,\mathrm dy}{\sqrt{x^2+y^2}} = \int_0^{\pi/2}\int_2^3 \frac{r\,\mathrm dr\,\mathrm d\theta}{\sqrt{r^2}} \\\\ = \int_0^{\pi/2}\int_2^3 \mathrm dr\,\mathrm d\theta \\\\ = \frac\pi2\int_2^3 \mathrm dr \\\\ = \frac\pi2r\bigg|_2^3 = \frac\pi2 (3-2) = \boxed{\frac\pi2}[/tex]

Instructions: Find the measure of the indicated angle to the nearest degree.

Answers

Answer:

? = 13.6

Step-by-step explanation:

Let the unknown angle be y

so

tan y= p/b

tan y =8/33

y = tan‐¹(8/33)

y = 13.62699486

y = 13.6

If(a²-1) x²+(a-1)x+a²-4a+3=0 is an identity in x, then find the value of a​

Answers

Answer:

Step-by-step explanation:

[tex](a^2-1)x^2+(a-1)x+a^2-4a+3=0\\\\Calculate\ and\ identify\ the\ polynomials\\\\\Longleftrightarrow\ a^2x^2-x^2+ax-x+a^2-4a+3=0\\\\\Longleftrightarrow\ a^2x^2+ax+a^2-4a+3=x^2+x+0\\\\\Longleftrightarrow\ \left\{\begin{array}{ccc}a^2&=&1\\a&=&1\\a^2-4a+3&=&0\\\end{array} \right.\\\\\Longleftrightarrow\ \left\{\begin{array}{ccc}(a-1)(a+1)&=&0\\a-1&=&0\\(a-1)(a-3)&=&0\\\end{array} \right.\\\\\\We\ must\ exclude\ a=-1\ and\ a=3\ (not\ solution)\\\Longrightarrow\ a=1\\[/tex]

51.Tandin Dorji was married to five women. First woman had three
daughters and five sons and the youngest wife had two sons. Two
of the remaining wives had one son each. If the ratio of children of
5th wife was 1:3 with the children of other wives. How many
children does Tandin have

Answers

Answer:

Tandin has 16 children.

Step-by-step explanation:

Total of children:

3+5 = 8(first woman)

2(youngest wife)

1 + 1 = 2(two of the  remaining wives)

So

8 + 2 + 2 = 12

If the ratio of children of  5th wife was 1:3 with the children of other wives.

Thus the 5th wife has 12/3 = 4 children.

How many  children does Tandin have?

12 + 4 = 16

Tandin has 16 children.

a2 - ab + 8b + b2 - 1

Answers

Answer:

а²-ab+8b+b²-1=a(a-b)+b(8+b)-1

True or False. A rational number can be expressed as the quotient a/b where b ≠ 0

Answers

Answer:

true. A rational number can be expressed as the quotient a/b where b ≠ 0

Manatees can swim in water up to 20 feet deep. Write an expression that represents the depth d, that a manatee can swim

Answers

Answer:

0 ≤ d ≤ 20

Step-by-step explanation:

You mention that Manatees can swim in water up to 20 feet deep. So, this means that the largest depth that he can swim is 20 feet, not more than this. Also, keep in mind that the depth can't be negative, so ----> 0 ≤ d ≤ 20 feet

We want to write an expression (an inequality actually) that defines the depth at which a manatee can swim. The inequality is: 0ft ≤ d ≤ 20ft.

We know that the manatees can swim in water up to 20 feet deep. This represents the maximum deep at which manatees can swim, the minimum is trivial, it would be 0ft (when the manatees are on the surface of the water).

Then we can write the inequality:

0ft ≤ d ≤ 20ft.

This gives the range of possible values of d, depth at which the manatee can swim.

If you want to learn more, you can read:

https://brainly.com/question/17675534

Cho hình hộp chữ nhật ABCD A B C D

Answers

Answer:

A B C D

A×B×C×D

3×3×3×6

162

Fill in the blanks.
(3b^3)^2 = _b^_

Answers

We can seperate (3b³) into two different parts, the constant and the variable.

The constant (3) and the variable (b) can both be squared and multiplied to get the correct answer, so:

3² = 9

(b³)² = [tex]b^{6}[/tex]

So, [tex](3b^{3})^{2} = 9b^{6}[/tex]

(PLEASE HELP ITS THE LAST QUESTION)

Find the measure of angle L.

A) 21.6°
B) 43.8°
C) 33.4°
D) 21.9°

Answers

Answer:

A

Step-by-step explanation:

lemme meh knw if it was helpful..

help giving brainilest, heart, and 5 stars ​

Answers

Answer:

4 = 6

5 = -17

Step-by-step explanation:

4. a² - b / b² - c

a² = 2² = 4

b = -2

4 - (-2) = 4 + 2 = 6

6 / b² - c = 6/4 - 3 = 6/1 = 6

4 = 6

5. -3x² + 2xy + 7

-3x² = -3 * -2² = -3 * 4 = -12

2xy = 2 * -2 * 3 = -4 * 3 = -12

-12 + -12 + 7 = -24 + 7 = -17

5 = -17

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

Describe what is the most difficult part of solving equations, for you personally.

Answers

What do you personaly feel like is most dificult.

For me its rembering minus signs

Getting everything in the proper spot. Like forming them as according to the formula because after that it’s pretty simple

Find the lengths the missing side

Answers

Answer:

Short leg = x

Longer leg = 12

Hypotenuse = y

Short leg = 4√3

longer leg = 12

Hypotenuse = 8√3

Answered by GAUTHMATH

A canoeist paddled down a river a distance of 2 miles in 45 minutes. Paddling up-stream on his return, it took him 90 minutes. Find the rate of the canoe in still water.

Answers

Speed of canoe in still water we will denote it CS and water itself has a speed we denote it WS. Downstream will be (CS + WS)*45 = 2, Upstream will be (CS - WS)*90 = 2. Solve the system you will find canoe speed in still water and the water speed as well. 90CS = 90WS +2, CS = WS+ 1/45 put it in the first function 90WS +1 = 2, WS = 1/90 miles per minute, CS =1/30 miles per minute.

create a graph of 4.95 + 3.99

Answers

Answer:

????

Step-by-step explanation:

as in y = 4.95 + 3.99 or points? if so just draw a horizontal line at 8.94

One positive number is 2 more than twice another. Their product is 180.
Step 2 of 2 : Find the numbers by solving the equation.

Answers

Answer:

9 and 20

Step-by-step explanation:

x = one number

y = 2x+2 = other number

xy = 190

x(2x+2) = 180

2x^2 +2x = 180

2x^2 +2x- 180 = 0

Factor out 2

x^2 +x -90 = 0

(x+10)(x-9) =0

Using the zero product property

x+10 = 0  x-9=0

x= -10  x=9

But they have to be positive

x = 9

y = 2x+2 = 2(9)+2 = 18+2 = 20

Aaron Lloyd what is a?

Answers

Answer:

Rugby lawyer

Step-by-step explanation:

Aaron is a partner in the firm’s dispute resolution division. He advises clients on a range of litigious and risk related matters, with particular expertise in the areas of corporate misconduct, white collar criminal and regulatory affairs, sports law and employment law.  Aaron leads our sports law practice, and is a member of the firm’s health and safety, public law, and organisational integrity teams.

Well regarded by clients for his ability to analyse and strategise complex situations, Aaron is internationally recognised for his ability to implement pragmatic and commercial strategies to minimise risk and create opportunity. This ability has resulted in clients avoiding significant litigation and commercial consequences.

Aaron is an experienced advocate, having argued cases in the District Court, High Court, Employment Court, the Court of Appeal and Supreme Court of New Zealand, along with numerous tribunals.

He is recognised by international legal directories including by Chambers & Partners (Asia Pacific), Who’s Who Legal, Expert Guides, Best Lawyers and Doyles.

Before joining MinterEllisonRuddWatts Aaron practiced as a barrister with Paul Davison QC, and has lectured at the University of Auckland.

Ellicott City Manufacturers, Inc., has sales of $6,344,210, and a gross profit margin of 67.3 percent. What is the firm's cost of goods sold? Round your final answer to the nearest dollar.

Answers

Answer:

$3792116

Step-by-step explanation:

that's the answer above

Can someone help me? I am struggling and I would be so happy if any of you helped me. Thank you for your help!

Answers

Answer:

Mean = 52

Standard Deviation = 13.64

Step-by-step explanation:

mean = 260/5

= 52

Standard Deviation = [tex]\sqrt{\frac{930}{5} }[/tex] = 13.64

I wasn't sure about my answer so used the Gauthmath app

If f(x) is an exponential function where f(-1.5) 26 and
f(5.5) = 7, then find the value of f(10), to the nearest hundredth.

Answers

Answer:

[tex]f(10) = 1147.25[/tex]

Step-by-step explanation:

Given

[tex]f(-1.5) = 26[/tex]

[tex]f(5.5) = 7[/tex]

Required

f(10)

An exponential function is represented as:

[tex]f(x) = ab^x[/tex]

[tex]f(-1.5) = 26[/tex] impleies that:

[tex]26 = ab^{-1.5}[/tex] --- (1)

[tex]f(5.5) = 7[/tex] implies that

[tex]7 = ab^{5.5}[/tex] --- (2)

Divide (2) by (1)

[tex]26/7 = ab^{-1.5}/ab^{5.5}[/tex]

[tex]3.71429 = b^{-1.5+5.5}[/tex]

[tex]3.71429 = b^{4}[/tex]

Take 4th root

[tex]b = 1.39[/tex]

Substitute [tex]b = 1.39[/tex] in [tex]26 = ab^{-1.5}[/tex]

[tex]26 = a * 1.39^{-1.5}[/tex]

[tex]26 = a * 0.6102[/tex]

Solve for (a)

[tex]a = 26/0.6102[/tex]

[tex]a = 42.61[/tex]

f(10) is calculated as:

[tex]f(10) = ab^{10}[/tex]

[tex]f(10) = 42.61 * 1.39^{10}[/tex]

[tex]f(10) = 1147.25[/tex]

Polymer composite materials have gained popularity because they have high strength to weight ratios and are relatively easy and inexpensive to manufacture. However, their nondegradable nature has prompted development of environmentally friendly composites using natural materials. The article "Properties of Waste Silk Shod Fiber/Cellulose Green Composite Films" (. of Composite Materials, 2012: 123-127) reported that for a sample of 10 specimens with 2% fiber content, the sample mean tensile strength (MPa) was 51.3 and the sample standard deviation was 1.2. Suppose the true average strength for 0% fibers (pure cellulose) is known to be 48 MPa. Does the data provide compelling evidence for concluding that true average strength for the WSF/cellulose composite exceeds this value?

Answers

Complete Question

Polymer composite materials have gained popularity because they have high strength to weight ratios and are relatively easy and inexpensive to manufacture. However, their nondegradable nature has prompted development of environmentally friendly composites using natural materials. An article reported that for a sample of 10 specimens with 2% fiber content, the sample mean tensile strength (MPa) was 51.1 and the sample standard deviation was 1.2. Suppose the true average strength for 0% fibers (pure cellulose) is known to be 48 MPa. Does the data provide compelling evidence for concluding that true average strength for the WSF/cellulose composite exceeds this value? (Use α = 0.05.)  

t=8.169  

P-value= ?

Answer:

a)  [tex]P-value=0[/tex]

b)  Hence,We FAil to reject the alternative hypothesis and accept that the true average strength for the WSF/  cellulose composite exceeds 48 MPa.

Step-by-step explanation:

From the question we are told that:

Sample size [tex]n=10[/tex]

Mean [tex]\=x= 51.3[/tex]

Standard deviation [tex]\sigma=1.2[/tex]

Significance level is taken as [tex]\alpha=0.05[/tex]

t test statistics

[tex]t=8.169[/tex]

Therefore

[tex]P-Value=P(t>8.169)[/tex]

Critical point

[tex]t_{\alpha,df}[/tex]

[tex]\alpha=0.05[/tex]

[tex]df=10-1=>9[/tex]

Therefore

P-value from T distribution table

[tex]P-value=0[/tex]

Conclusion

[tex]P-value (0)< \alpha(0.05)[/tex]

We Reject the Null Hypothesis [tex]H_0[/tex]

Hence,We FAil to reject the alternative hypothesis and accept that the true average strength for the WSF/  cellulose composite exceeds 48 MPa.

The length of the hypotenuse of a 30​ -60 ​-90 triangle is 32. What are the lengths of the​ legs?

Answers

Answer:

16, 16(sqrt3)

Step-by-step explanation:

30-60-90 triangles follow a rule where the hypotenuse is 2 times the shortest leg, and the longer leg is sqrt3 times the shorter leg.

So, the sides are x, 2x, and (sqrt3)x.

If 2x = 32, then x = 16.

Therefore the two legs are 16 and 16(sqrt3)

you can search up 30-60-90 triangle for more information

There are 768 beds in a hospital.

Each floor has 64 beds.

How many floors are there?

Answers

Answer:

12 floors

Step-by-step explanation:

768 ÷ 64 = 12.

Answer:

12

Step-by-step explanation:

768 divided by 64 =12

Abigail buys two cartons of strawberries. One carton has 191919 berries and the other carton has 262626 berries. She wants to divide the berries into bags so there are exactly 666 berries in each bag.
How many bags will have 666 berries?

Answers

Abigail will have 682 bags full with 666 berries.

Answer:

682

Step-by-step explanation:

191,919 + 262,626

454545 ÷ 666 = 682.5

Thus meaning 682 bags will have 666 berries and one bag will have 333 berries.

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