Using the digits 1-9 , at most one time each, to fill the blanks. how many ways can you find to do this? lim

Answers

Answer 1

[tex]Solution(1)Digit 1 to 9Lef $x \rightarrow 1, x^{\prime}$$$\lim _{x \rightarrow 1}=1^{\prime}=1$$$\lim _{\lim ^9}=(1)^9=1$$[9$ ways $]$Similarlyt$$\lim _{x \rightarrow 2} x^{\prime}=2^{\prime}=2$$$\lim _{x \rightarrow 2} x^9=\lim _{x \rightarrow 2} 2^9=512 \quad[9$ ways $]$Total no. of ways $=9 \times 9=81$ ways.Required No, of ways $=81$ Ans[/tex]

What is limit?

This article discusses the idea of limit in general. See Limit of a sequence and Limit of a function for additional detailed situations. See Mathematics (limit) for further usage.

Limits are crucial to calculus and mathematical analysis because they are needed to determine continuity, derivatives, and integrals. Limits are the value that a function (or sequence) approaches when the input (or index) approaches some value.

In addition to being closely connected to limit and direct limit in category theory, the idea of a limit of a sequence is further expanded to include the idea of a limit of a topological net.

To know more about limit, visit;

https://brainly.com/question/8533149

#SPJ4


Related Questions

Number 13 and 9 please

Answers

Answer:

9.5>6      41.8>0

Step-by-step explanation:

Which of the following graphs represents a function that has a positive
leading coefficient? Check all that apply.
+
A.
B.
A. Graph A
B. Graph B
C. Graph C
D. Graph D
N N
C.
D.
finance
SURPRISE!
Here's a $10
financet
Instant Cred

Answers

Answer:

b , d

Step-by-step explanation:

richard cuts a $ 4\frac{1}{2} ~\text{ft} \times 7\frac{1}{2} ~\text{ft} \times 11\frac{1}{4}~ \text{ft}$ rectangular prism into congruent cubes without any part of the prism leftover. if he makes the cubes as large as possible, how many will he produce?

Answers

If he makes the cubes as large as possible, the maximum number of cubes is equal to 900 cubes.

How to determine the number of cubes?

In order to determine the number of cubes that would be produced by Richard when the rectangular prism is cut into congruent cubes without any part of the rectangular prism leftover, we would make the edges of the cube 100 times larger and then evaluate:

Length of cube = 4 1/2 ft × 100 = 450 feet.Breadth of cube = 7 1/2 ft × 100 = 750 feet.Height of cube = 11 1/4 ft × 100 = 1125 feet.

Note: The greatest common factor (GCF) of the dimensions above is 75.

Next, we would divide each of the dimension by 75:

Length of cube = = 450/75 = 6 feet.

Breadth of cube = 750/75 = 10 feet.

Height of cube = 1125/75 = 15 feet.

Therefore, the maximum number of cubes is given by:

Maximum number of cubes = 6 × 10 × 15

Maximum number of cubes = 900 cubes.

Read more on number of cubes here: https://brainly.com/question/26229299

#SPJ4

Complete Question:

Richard cuts a 4 1/2 ft × 7 1/2 ft × 11 1/4 ft rectangular prism into congruent cubes without any part of the prism leftover. If he makes the cubes as large as possible, how many will he produce?

A sample of n=225 scores has =103 and s2 =16. what is the sample standard deviation?

Answers

Based on the calculations, the sample standard deviation is equal to 4.

What is a z-value?

A z-value is also referred to as a z-score or standard score and it can be defined as a measure of the distance between a raw score and the mean, when standard deviation units are used.

In Statistics, z-values can either be positive or negative and it can be calculated by using this formula:

[tex]Z=\frac{\bar x\;-\;u}{\delta}[/tex]

Where:

x is the sample mean or observed data.u is the mean.δ is the standard deviation.

In Statistics, the standard deviation of a data sample is the square root of the variance and as such, this given by:

Note: Variance, δ² = 16

Taking the square root of the variance, we have:

Standard deviation, δ = √16

Standard deviation, δ = 4.

Read more on standard deviation here: https://brainly.com/question/28426562

#SPJ4

Complete Question:

A sample of n=225 scores has [tex]\bar x[/tex] = 103 and δ² = 16. What is the sample standard deviation?

PLEASE HELP WILL MARK BRAINLIEST

Answers

Answer:y=-3, x=6

Step-by-step explanation:

Answer:

x=6 y=-3

Step-by-step explanation:

If two pounds of meat will serve 5 people, how many pounds will be needed to serve 13
people?

Answers

Answer:

Step-by-step explanation:

2 pounds / 5 people

x pounds / 13 people

2/5 pounds per person so 2/5 * 13 = 26/5

5 1/5 i think

sorry if its wrong

Answer: The answer of the question is 2 and 3/5.

Step-by-step explanation: Every pound of meat serves one person, because 10 divided by 2 people is 5. Then, there are 3 pieces of meat left over, and since every person eats 5/5, or 1 whole, then there are 3/5 pieces left over. You then add 2 and 3/5 together, getting your answer 2 3/5.

As the degrees of freedom increase, the t distribution approaches the _____ distribution. a. exponential b. p c. normal d. uniform

Answers

As the degrees of freedom (DF) increase, the t distribution approaches the normal distribution. Therefore, the correct answer option is: C. normal distribution.

What is the degrees of freedom (DF)?

The degrees of freedom (DF) in a sample are typically used to correct a possible bias that exists between the alternative and null hypotheses because they are the maximum number of logically independent numerical values (data points) in the final calculation of a statistical problem.

What is a normal distribution?

A normal distribution is sometimes referred to as the Gaussian distribution and it can be defined as a probability distribution that is continuous and symmetrical on both sides of the mean, which shows that all data near the mean have a higher frequency than data that are far from the mean.

In this context, we can reasonably infer and logically deduce that the t-distribution generally approaches the normal distribution as the degrees of freedom (DF) increase.

Read more on degrees of freedom here: https://brainly.com/question/22849398

#SPJ4

if <1 and <2 form a linear pair and m<1 is 18 degrees less than five times the measure of <2 find m<1

Answers

∠1 and ∠2 will have the values 33° and 147° respectively when they form a Linear Pair.

In the question, It is given that ∠1 and ∠2 form a Linear Pair.

So, ∠1 and ∠2 = 180°, Also it is stated that ∠1 is 18° lesser than 5 times ∠2.

Taking ∠2 = x we get ∠1 = 5x-18

Now for Linear Pair, we have ∠1 + ∠2 = 180°

putting values of ∠1 and ∠2  we get :  (5x-18) + x = 180

Solving the equation  => (5x-18) + x = 180   =>   6x = 198

=>  x = 33

Putting the value of x in both ∠1 and ∠2  we get :

∠2 = 33°  and ∠1  = 5(33) - 18 =>  ∠1  = 147°

Hence, we get ∠1 and ∠2  measures 147° and 33° respectively.

To know more about Linear Pair, Click here :

https://brainly.com/question/28522502

#SPJ1

The probability that Bob will make a free throw is 3/4 . What is the probability that Bob will make his next 2 free throws.

Answers

Answer:

9/16

Step-by-step explanation:

Salome's house went from a valuation of 4.5 million ZAR (South African Rand) on 1st January
2011, to 6 million ZAR on 1st January 2020.

If the value of the house compounded monthly, what was the annual rate of increase?

Give your answer as a percentage, correct to 1 decimal place.

Answers

Using compound interest, it is found that the annual rate of increase was of 3.10%.

What is compound interest?

The amount of money earned, in compound interest, after t years, is given by:

[tex]A(t) = P\left(1 + \frac{r}{n}\right)^{nt}[/tex]

In which:

A(t) is the amount of money after t years. P is the principal(the initial sum of money). r is the interest rate(as a decimal value). n is the number of times that interest is compounded per year.

For this problem, the parameters are given as follows:

t = 9, A(t) = 6, A(0) = 4.5, n = 12.

Hence we solve for r to find the interest rate as follows:

[tex]A(t) = P\left(1 + \frac{r}{n}\right)^{nt}[/tex]

[tex]6 = 4.5\left(1 + \frac{r}{12}\right)^{12 \times 9}[/tex]

[tex]1 + \frac{r}{12}\right)^{108} = 1.33[/tex]

[tex]\sqrt[108]{1 + \frac{r}{12}\right)^{108}} = \sqrt[108]{1.33}[/tex]

[tex]1 + \frac{r}{12} = (1.33)^{\frac{1}{108}}[/tex]

1 + r/12 = 1.0026.

r/12 = 0.0026

r = 12 x 0.0026

r = 0.031.

The annual rate of increase was of 3.10%.

More can be learned about compound interest at https://brainly.com/question/24924853

#SPJ1


9. The table shows the relationship between the number of targets a person
hits in a game of laser tag and that person's score.
Targets hit
3
4 5 6
Score
8 16 24 32 40 48
0 1 2
0

Answers

The table shows relationship between the number of targets a person

hits in a game of laser tag and that score of that person. The table shows is a continuous graph.

What is a continuous function in a graph?

As the name implies, a continuous function is one whose graph is continuous throughout without any pauses or leaps. To put it another way, we say that a function is continuous if we can draw the curve (graph) of the function without ever picking up the pencil. In calculus, learning about a function's continuity is crucial since without it, a function cannot be differentiated.

If a function's graph is a continuous curve without any holes, gaps, or breaks, it is said to be continuous.

Now,

x-axis on the graph show "Target hit" and y-axis shows "Score"

Graph the points using a graphing calculator.

To know more about continuous graph visit: https://brainly.com/question/9697809

#SPJ9

The complete question is:

"The table shows the relationship between the number of targets a person

hits in a game of laser tag and that person's score.

Target hit  0   1    2     3     4     5    6

Score        0   8   16  24   32   40   48"

Consider this equation. (4x)1/3 - x = 0 The first step in solving this equation is to ___The second step is to ____ Solving this equation for x initially yields _____ Checking the solutions shows that _____

Answers

The first step is to move -x to RHS and second step is to solve to get the value of x. The solutions will be x = -2 , 0 , 2.

What is algebra ?

Algebra is the branch that deals with various symbols and the arithmetic operations such as addition , subtraction , division , etc.

The equation given is [tex]4x^{1/3}[/tex]- x = 0

We need to solve it stepwise.

The first step will be to to move -x to RHS.

[tex]4x^{1/3}[/tex]- x = 0

or

[tex]4x^{1/3}[/tex] = x

The second step is to solve to get the values of x.

4x = x³

4x - x³ = 0

x (4 - x²) = 0

So , this will give us two equations which are ,

x = 0

and

4 - x² = 0

or

x² = 4

x = ± 2

So , solving the equation for x initially yields two equations which are x = 0 and 4 - x² = 0 and the solution we get is x = 0 , 2 , - 2.

Thus , the solutions will be x = -2, 0, 2.

Learn more about algebra here ;

brainly.com/question/26479183

#SPJ1

Find each quotient a7/12÷1/7b -0.05÷(5/8÷1/2) c6 1/4÷(-5/16) d-1÷-(10/13)

Answers

The quotient of the problem given are 49/12, -1/25, -20 and 13/10 respectively

These are the simple problems of fractions

A) 7/12 ÷ 1/7

   7/12×7/1

    49/12

B) -0.05 ÷(5/8 ÷ 1/2)

 - 5/100 ÷ ( 5/8 ×2/1)

  -5/100÷ (5/4)

  -5/100 ×4/5

   -1/25

C) 6 1/4 ÷(-5/16)

   25/4 × (-16/5)

  -20

D) -1 ÷(-10/13)

   -1 ×(-13/10)

    13/10

To know more about fractions - https://brainly.com/question/8627637

#SPJ9

express 121,200 in exponential (powers of 10) notation. express the earth sun distance in kilometers in powers of 10 notation.

Answers

The exponential form of given number 121200 is 1.212 × [tex]10^5[/tex]

And the earth sun distance in kilometers in powers of 10 notation is 1.5 × [tex]10^8[/tex]

For given question,

We need to express 121,200 in exponential (powers of 10) notation.

To use scientific notation, pick a value between 1 and 10, then multiply it by 10ˣ.

The number between 1 and 10 in 121200 is 1.212 with 5 decimal points.

So, the exponential notation of given number would be,

121,200 = 1.212 × [tex]10^5[/tex]

Earth's average distance from the Sun is around 93 million miles (150 million kilometers). That's one AU.

So the number between 1 and 10 in 150,000,000 is 1.5, with 8 decimal points.

So, the distance between he Earth and the Sun is:

150,000,000 = 1.5 × 10⁸

Therefore, the exponential form of given number 121200 is 1.212 × [tex]10^5[/tex]

And the earth sun distance in kilometers in powers of 10 notation is 1.5 × [tex]10^8[/tex]

Learn more about the powers of 10 here:

https://brainly.com/question/13303295

#SPJ4

this is a super difficult math worksheet for me so please help ASAP

Answers

Answer:

Step-by-step explanation:

function notation

1) -13

2) -4

3) 7

4) 23

5) 13

6) -4

7) 14

8) -1

9) 15

10) 0

function operations

1) -3x^2 + 11x -4

2) 6x - 12

3) 3x^2 - 2x + 5

4) x^2 - 4x + 5

5) 27x^2 - 32x

6) 2x^5 + 4x^4 - 5x^3 - 10x^2

7) -6x^4 + 8x^3 + 15x^2 - 20x

8) 3x^4 - 2x^3 - 16x^2

65.28 ÷ 12
round it to the nearest tenth If necessary.​

Answers

Answer:

5.44

Step-by-step explanation:

Help with problem 20 please​

Answers

The rate of change will be 0.074 grams per year.

How to calculate the rate?

The change in hydrocarbon will be:

= 3.4 - 0.8

= 2.6

The number of years will be:

= 2007 - 1972

= 35

Therefore, the rate will be:

= Change in hydrocarbon / Years

= 2.6 / 35

= 0.074 grams per year.

Learn more about rates on:

brainly.com/question/25537936

#SPJ1

please help i will give out brainlist

Answers

Based on the definition of supplementary angles:

x = 5

The measure of angle 6 = 30°

What are Supplementary Angles?

If two angles are supplementary, when added together, their sum will equal 180 degrees.

We known that angles 5 and 6 are supplementary angles. Therefore, it means their sum would be equal to 180 degrees.

Hence, we would have the following equation:

m<5 + m<6 = 180

Substitute

40x - 50 + 5x + 5 = 180

Add like terms

45x - 45 = 180

45x = 180 + 45

45x = 225

45x/45 = 225/45

x = 5

The measure of angle 6 = 5x + 5 = 5(5) + 5

The measure of angle 6 = 30°

Learn more about supplementary angles on:

https://brainly.com/question/8992900

#SPJ1

On a road map, the distance from City A to City B is 4 inches. The map scale is 1 inch = 20 miles. What is the actual distance, in miles, between City A and City B?

Answers

80 miles.

1 x y = 20 x 4

Y = 80

Which built-in data type stores only whole numbers? a. whole b. number c. float d. int

Answers

The built-in data type that stores only whole numbers is int data type

Built-in data types are the data  types used to declare and store the variables in the program, They are also known as primary data types

Int data type is a data type that can store the whole number. The range of int data type is from -2147483648 to 2147483647.

Here,

Here the condition is a built-in data type stores only whole numbers

So, the int data types satisfy these conditions

Hence, the built-in data type that stores only whole numbers is int data type

Learn more about about int data type here

brainly.com/question/19905770

#SPJ4

One of two supplementary angles measures 6 degrees less than twice
the other. How large are the angles?

Answers

Answer:

adding them together, x+2x−6=180 . this can be solved algebraically. the smaller angle is 62∘ . the supplement to that, 2x−6 , is (124−6)∘ , which is 118∘ .

I need help asap!!!!

Answers

Answer: The first one is correct.

Step-by-step explanation:

x = 3
y = -2
So: 2 x 3 + 2 x (-2) = 6 + (-12) = -6

Write the equation of the line that is perpendicular to y = 2x+4 and passes through the
point (-4,-1).
y =____________ X+

Answers

Answer: (Likely) y = -2x

Step-by-step explanation:

1. We know the line y = 2x + 4, it intersects 4 and it's rate of change is 2. We also know the point it is passing, (-4,-1).

2. With this info, It is best to confirm the slope is likely -2, since it is likely that lines when perpendicular are likely to be congruent.

3. So, how about the y intercept? Well, it's simple as well, we will substitute x for 0, and 2 times 0 equals 0, and y = 0, so the perpendicular line is y = -2x

consider a little league team that has 13 players on its roster. a. how many ways are there to select 9 players for the starting lineup? b. how many ways are there to select 9 players for the starting lineup and a batting order for the 9 starters? c. suppose 6 of the 13 players are left-handed. how many ways are there to select 3 left-handed outfielders and have all other 6 positions occupied by right-handed players?

Answers

There are 715 ways to select 9 players for the starting lineup.

Permutation is used whenever there is arrangement or where order is important . denoted by [tex]P(n,r)=\frac{n!}{(n-r)!}[/tex]

n= no of item  , r = no of items to be arranged.

Combination is used when there is selection . denoted by[tex]C(n,r)=\frac{n!}{r!(n-r)!}[/tex]

n=no of item  , r= no of item to be selected.

Part (a)

In the given question

we have to select 9 players out of 13 player , combination will be used

[tex]C(13,9)=\frac{13!}{9!*(13-9)!}=\frac{13*12*11*10*9!}{9!*4!} =\frac{13*12*11*10}{4*3*2}[/tex]=715 ways.

Part(b)

In this part we have to find how many ways are there to select 9 players for the starting lineup and a batting order for the 9 starters.

Since the batting order is important , permutation will be used.

[tex]P(13,9)=\frac{13!}{4!} =\frac{13*12*11*10*9*8*7*6*5*4!}{4!} =13*12*11*10*9*8*7*6*5[/tex]

=259459200 ways.

Part(c)

In this part we have to do selection of  3 left-handed outfielders and have all other 6 positions occupied by right-handed players.

Since order is not important Combination  will be used.

To select 3 left handers from total 6 left handers = C(6,3)

& to select 6 positions of left handers from remaining 7 right handers=C(7,6)

No of ways of selection = C(6,3)*C(7,6)

[tex]=\frac{6!}{3!*(6-3)!} *\frac{7!}{6!*(7-6)!} \\ \\= \frac{6!}{3!*3!} *\frac{7!}{6!*1!} \\ \\[/tex]

On solving further we get

[tex]= \frac{7!}{3!*3!} =\frac{7*6*5*4*3!}{3!*3*2*1} =7*5*4=140ways[/tex]

Therefore ,(a)There are 715 ways to select 9 players for the starting lineup.

(b) there are 259459200 ways to to select 9 players for the starting lineup and a batting order for the 9 starters and 140 ways .

(c)there are 140 ways to select 3 left-handed outfielders and have all other 6 positions occupied by right-handed players.

Learn more about Permutation& Combination here https://brainly.com/question/13480867

#SPJ4

The diagram shows three lines with some marked angle measures.
?
?
70°
?
?
53°
?
Find the missing angle
measures marked with
question marks.

Answers

The first intersection of the geometric system generates two vertical angles of 70° and two vertical angles of 110° and the second intersection of the geometric system generates two vertical angles of 53° and two vertical angles of 127°.

How to determine the measures of the missing angles of a geometric system

In this question we have a geometric system generated by three lines, where two lines pass through the first lines and four angles are generated on each intersection. The measures of the missing angles can be found by the following concepts:

Vertical angles - Two angles opposite to each other have the same measure.Supplementary angles - Two angles adjacent to each other that a total measure of 180°.

The first intersection of the geometric system generates two vertical angles of 70° and two vertical angles of 110° and the second intersection of the geometric system generates two vertical angles of 53° and two vertical angles of 127°.

To learn more on vertical angles: https://brainly.com/question/10668231

#SPJ1

Find the midpoint of the segment with the given endpoints.
​(​-2,2​) and ​(10​,0​)

Answers

Answer:

I think it’s (4,1)

Nate is looking for a repair service for general household maintenance. One
service charges $75 to join the service and $30 per hour. Another service charges
$15 to join the service and $40 per hour. After how many hours of service is the
total cost for the two services the same?

Answers

Answer: Total cost for the two services of hours = $6.

Step-by-step explanation:

Given data,

Nate is looking for a repair service for general household maintenance.

First service charges = $75

First service charge per hour = $30 per hour

Another service charges = $15

Another service charge per hour = $40 per hour

Total cost of hours of service is = x

So,

We can write,

                          75 + 30x = 15 + 40x

Rearrange variables to the left side of the equation,

                          30x - 40x = 15 - 75

Combine like terms,

                                  -10x = 15 - 75

Calculate the sum or difference,

                                    -10x = -60

Divide both sides of the equation by the coefficient variable,

                                      x = -60/-10

Determine the sign for multiplication or division,

                                      x = 60/10

Cross out the common factor,

                                       x = 6

Therefore,

Total cost for the two services of hours = $6.

Learn more about event correlation here: brainly.com/question/625312

#SPJ9

Determine the total number of roots f(x) = (3x^4 + 1)^2

Answers

[tex]f(x) = (3 {x}^{4} + 1) {}^{2} \\ f(x) = 0 \\ (3 {x}^{4} + 1) {}^{2} = 0 \\ 3x {}^{4} + 1 = 0 \\ 3x {}^{4} = -1 \\ x {}^{4} = \frac{ - 1}{3} [/tex]

[tex]f(x) \: admits \: no \: real \: roots[/tex]


W X Y Z is a square. If W T=3 , find each measure. m∠WTZ

Answers

Step-by-step explanation:

In this exercise we have to use the knowledge of quadrilaterals to calculate the measures of each side of the square, in this way we can say that it will be valid:

Given in the exercise that each the value of:

WT=3

The diagonals  of a square are congruent, and bisect each other, that will help to find:

16. SHORT RESPONSE The first story of a building is 24 feet high, and each

additional story is 18 feet high. Write an expression for the height to the top

of the nth story. Explain the meaning of each term in the expression

Answers

The height to the top of the nth story of the building is  ( 24 + 18(n-1) ).

Height of first story of a building = 24 feet

Height of each additional story = 18 feet

Total number of stories in a building = n

The Height of first story of a building is fixed to be 24 feet and Height of each additional story is 18 feet. We first need to calculate total number of additional stories to write an equation.

The total number of additional stories =  ( total number of stories in a building - 1) = (n-1)

The height of total additional stories = 18 (n-1)

Total height of the building = (Height of first story of a building + height of total additional stories) = ( 24 + 18(n-1) ).

The height to the top of the nth story of the building is  ( 24 + 18(n-1) ).

To know more about Solving Quadratic equations refer to the link:

brainly.com/question/18117039

#SPJ4

Other Questions
by the end of the seventeenth century, indentured servants who gained their freedom often gained great wealth as more land opened for settlement. Who tends to issue junk bonds? a. financially troubled firms. b. foreign governments. c. local governments in the united states. d. the federal reserve. Which term is not associated with urie bronfenbrenner's ecological-systems approach? When demand for a product is low, the producer will Which country claimed the area indicated by the number 1? What volume of a 0.270 m naf0.270 m naf solution is required to react completely with 535 ml535 ml of a 0.700 m srcl20.700 m srcl2 solution? Indian history since the 11th century has seen much conflict between which two groups? Greeks and Persians Byzantines and Sassanids Mughals and Mamluks Hindus and Muslims As perceived by an examiner, which is an objective finding such as a fever, a rash, or the whisper heard over the chest in pleural effusion? Help me with this pls I will make brainlest In the united states, fire departments respond to an average of _________ fire calls annually Andrew made an error in determining the polynomial equation of smallest degree whose roots are 3, 2+2i and. Review Andrews work, identify the error and correct all work from that point forward that is affected by this error. Include at least one sentence explaining his error. Use proper mathematical vocabulary, appropriately. What are the two independent methods used in dating events in earth's history? select all that apply. ? QuestionLook at your annotations and the notes you made in your notebook. How do Mandela's calls to action work to developanother central idea of his speech?O He is expressing his happiness at being elected president.O He is highlighting the need for South Africa to reflect on its past.He is asking people to change and move forward from the past.O He is warning of the dangers facing the country's future.Submit plato What is geographyPLSS HELP ME I NEED IT ASAP Writing a policy is not always as easy as it seems. however, the prudent security manager always scours available resources for __________ that may be adapted to the organization. baby sean has cystic fibrosis, which causes thick mucus secretions that can block ducts like the pancreatic duct, leading to insufficient enzymes in the small intestine. why are these enzymes important? HELPHugo is pumping regular gas into his truck. Write and solve an absolute value equation to represent how many gallons of gas will be pumped when the total is $25 plus or minus $0.50. My poem please rate I knew the day we meant we were meant to be I knew our fate was set thatyou were the one for me Referring to the Fig. in Question #26, find the product represented by theshaded region. Vasco Nunez de Balboa discovered what body of water?1. The Mississippi River2. The Missouri River3. The Pacific Ocean4. The Indian River