Prove that the cube root of 2 is irrational.

Answers

Answer 1
The cube root of 2 is irrational. The proof that the square root of 2 is irrational may be used, with only slight modification. Assume the cube root of 2 is rational. Then, it may be written as a/b, where a and b are integers with no common factors. (This is possible for all nonzero rational numbers). Since a/b is the cube root of 2, its cube must equal 2. That is, (a/b)3 = 2 a3/b3 = 2 a3 = 2b3. The right side is even, so the left side must be even also, thatis, a3 is even. Since a3 is even, a is also even (because the cube of an odd number is always odd). Since a is even, there exists an integer c such that a = 2c. Now, (2c)3 = 2b3 8c3 = 2b3 4c3 = b3. The left side is now even, so the right side must be even too. The product of two odd numbers is always odd, so b3 cannot be odd; it must be even. Therefore b is even as well. Since a and b are both even, the fraction a/b is not in lowest terms, thus contradicting our initial assumption. Since the initial assumption cannot have been true, it must be false, and the cube root of 2 is irrational.

Related Questions

how do you solve this absolute value equation? ∣x−2∣=∣4+x∣

Answers

l x - 2 l = l 4 + x l

Remember : Absolute is just the distance from zero.

Ex : l -4 l turns into 4, as it is 4 spaces away from zero on a number line :)

l x - 2 l turns into x + 2

l 4 + x l stays the same.

So, our equation now looks like this :

x + 2 = 4 + x

So, we're basically just trying to get x by itself.

So, subtract 2 from both sides.

x = 4 + x - 2

Then, subtract x from both sides.

x - x = 4 -2 

0 = 2

Therefore, there are no solutions to this equation :)

~Hope I helped!~

Find the coordinates of the midpoint of ab with endpoints a(-10,3) and b(2,-2) worksheet answers

Answers

-10+2/2 and 3-2/2
(-4;1/2)

The number of hours per week that the television is turned on is determined for each family in a sample. the mean of the data is 3030 hours and the median is 26.226.2 hours. twenty-four of the families in the sample turned on the television for 1515 hours or less for the week. the 11th11th percentile of the data is 1515 hours. step 2 of 5 : approximately how many families are in the sample? round your answer to the nearest integer.

Answers

Go to papa math,tiger algebra,picture math!!!!!!

How to find slope and y intercept 6x-5y=15?

Answers

we need to put this equation in y = mx + b form because in this form, the slope will be in the m position and the y intercept will be in the b position. So basically, we solve for y.

6x - 5y = 15 ....subtract 6x from both sides
-5y = -6x + 15...divide both sides by -5
(-5/-5)y = (-6/-5)x + (15/-5)...simplify
y = 6/5x - 3

y = mx + b...remember, m is ur slope and b is ur y int
y = (6/5)x + (-3).....ur slope(m) = 6/5 and ur y int (b) = -3

I need hellllllllllllllllllllppppp for this trigonometry question

Answers

see attached picture:

the vertical change is the Y calculation

Marks canoes rents for $20 plus $35 per hour you do not want to spend more than $1.50.for how many hours can you afford to rent the canoe

Answers

You can get 3 hours in because $150-$20= $130
$130/35=3.7 hours but since he can’t spend over that amount it would be 3 hours
3 hours will be your answer.
Have a blessed day/night.

Determine whether the quantitative variable is discrete or continuous. number of lightning strikes in a city in one year'

Answers

The number of lightning strikes will be a whole number

Therefore it is a discrete variable
That quantitative variable is discrete because you only get one answer when your figuring out how many lightning strikes in a city in one year.

which number belongs to the solution set of the equation below? 9x=114
A.14
B.16
C.12
D.18

Answers

its C.

You divide 114 / 9 and get your answer
Hi there!

9x = 114
Divide both sides by 9
9x/9 = 114/9
x = 38/3
In decimal it is x = 12.666667

So, C is the correct answer!
I hope I helped!

What is the area of a triangle whose vertices are
R(−4, 2),S(1, 2), and T(−5, −4)?
 
Enter your answer in the box

Answers

ANSWER

15 square units.

EXPLANATION

This triangle has one of its height(altitudes) falling outside the triangle.

We determine the base using absolute value method. This is because the coordinates of [tex]R(-4,2)[/tex] and [tex]S(1,2)[/tex] tell us that this line is horizontal. The y-values are constant.

Therefore [tex]|RS|=|1--4|[/tex]

[tex]\Rightarrow |RS|=|1+4|[/tex]

[tex]\Rightarrow |RS|=|5|[/tex]

[tex]\Rightarrow |RS|=5[/tex]

Also

The triangle is bounded between [tex]y=2[/tex] and [tex]y=-4[/tex].

Therefore the vertical height of interest,

[tex]|RT|=|-4-2|[/tex]

[tex]|RT|=|-6|[/tex]

[tex]|RT|=6[/tex]

We can now find the area using the formula

[tex]Area=\frac{1}{2}base\times height[/tex]

[tex]Area=\frac{1}{2}\times6 \times 5[/tex]

[tex]Area=3 \times 5[/tex]

[tex]Area=15[/tex] square units

A horizontal line passes through the point (5, –1). Which point is also on this line?
A.(0, 0)
B.(–1, 5)
C.(5, –4)
D.(–2, –1)

Answers

A horizontal line is one that goes from left to right. This means that the X value can change, but the Y value cannot. So we just look for an answer where the X value changes and we know that C is correct, (5, -4)

Hope this helps! If you have any questions just ask!

Answer: -2,-1

Step-by-step explanation

If a horizontal line passes through the point (5;-1) then the equation if this line: y=-1

Each point (x;-1) is also on this line.

Factor this polynomial using the GCF: 3xy^2 + 3xy^2 - 3xy


3xy(y + x - 1)


-3xy(y + x + 1)


3x(y2 + x - 1)


3x^2(y2 + 1 - 1)

Answers

3xy^2 + 3yx^2 - 3xy....GCF is 3xy

3xy(y + x - 1) <==

Kristen bought 2 candy bars for $1.29 each and a soda for$1.99. She had to pay $0.38 in tax. How much was her bill?

Answers

Answer:

$4.95

Step-by-step explanation:

1.29 * 2 = 2.58 + 1.99 = 4.57

4.57 + .38 = 4.95

If a number is rational then it must be a whole number true or false

Answers

False, because rational numbers are mostly fractions which isn't exactly a whole number

5/16t=-9

Plz help me ASAP and show all of the steps that you did! PLEASE HELP!!! :) 10 POINTS!!!!!

Answers

I'm going to assume that the equation is [tex]\frac{5}{16}t = -9[/tex] where the 't' is not in the denominator

If that assumption is correct, then we do two things to solve for t. First, we multiply both sides by 16. This undoes the division of 16 on the left side

[tex]\frac{5}{16}t = -9[/tex]

[tex]16*\frac{5}{16}t = 16*(-9)[/tex]

[tex]5t = -144[/tex]

-------------------------------

Then we divide both sides by 5 to undo the multiplication of 5 (note: 5t means 5*t or "5 times t")

[tex]5t = -144[/tex]

[tex]\frac{5t}{5} = \frac{-144}{5}[/tex]

[tex]t = -\frac{144}{5}[/tex]

-------------------------------

So here's what all the steps look like:

[tex]\frac{5}{16}t = -9[/tex]

[tex]16*\frac{5}{16}t = 16*(-9)[/tex]

[tex]5t = -144[/tex]

[tex]\frac{5t}{5} = \frac{-144}{5}[/tex]

[tex]t = -\frac{144}{5}[/tex]

note: -144/5 converts to the decimal value of -28.8 so t = -144/5 is the same as t = -28.8

The length of a rectangle is twice its width. if the perimeter of the rectangle is 54 ft , find its length and width.

Answers

Let w be the width.

2(2w) + 2w = 54.

4w+2w = 54
6w=54.
w=9
So length equals twice that...I think you can solve that on your own. xD

If f(x)=x^2-3x,find f(-1.8). Show all work

Answers

Answer:  f(-1.8) =  8.6  .
____________________________________________________

Basically, plug in "(-1.8)" for "x" ; and solve:

Given:  f(x) = x² − 3x ;
____________________________________________________
            f(-1.8) = (-1.8)²  −  3(-1.8) ;

            f(-1.8) = [(-1.8)*(-1.8)]  − [3(-1.8)] ;

            f(-1.8) =  3.24  − (-5.4) ;
    
            f(-1.8) =  3.24  +  5.4 ;

            f(-1.8) =  8.6  .
____________________________________________________
            

The value of f(x) = x²-3x at x = -1.8 is -2.16.

What is a quadratic function?

A polynomial function with one or more variables, where the largest exponent of the variable is two, is referred to as a quadratic function. In other terms, a "polynomial function of degree 2" is a quadratic function.

We have the quadratic function:

f(x) = x²-3x

So, to find the value at x = -1.8:

Substitute the value to the function.

f(-1.8) = (-1.8)²-3(-1.8)

f(-1.8) = 3.24 - 5.4

f(-1.8) = -2.16

Therefore, the value is -2.16.

To learn more about the quadratic function;

https://brainly.com/question/11485644

#SPJ2

while on vacation, your family budgeted $550 for food. Your family went to the grocery store for drinks and snacks and spent $67.19 Each meal you are going to eat out had a budget of $55

Which expression describes the amount of money left in your after you consume your meals ?

A. 550 - (67.19 + 55x)
B.550- x(67.19 -55)
C.550-x(67.19+55)
D.550-(67.19-55x)

Answers

550 for food...u spent 67.19 for drinks and snacks....u spent 55 for each meal (x)

so ur equation would be : 550 - (67.19 + 55x)

Final answer:

The correct expression to calculate the remaining budget for food after spending on groceries and meals out is 550 - (67.19 + 55x), which is option A.

Explanation:

The question asks us to determine which expression correctly represents the amount of money left in the budget for food after the family has spent money on groceries and consumed their meals. The original budget for food is $550, and the family spent $67.19 on drinks and snacks. Each meal they plan to eat out is budgeted at $55. Let's denote the number of meals the family will eat out as 'x'.

To calculate the remaining budget after these expenses, we subtract the cost of groceries and the total cost of eating out (which is $55 times the number of meals 'x'), from the original budget for food. The correct mathematical expression for the remaining budget is:

550 - (67.19 + 55x)

This expression is represented by option A. This correctly factors in the initial expenditure on groceries of $67.19 and then subtracts $55 for each meal 'x' from the remaining budget.

what would 3/4 - 3/4 be?

Answers

Anything subtracted by itself is 0

So, the answer is 0.

Hope this helped!
3/4 minus 3/4 would be 0. hope you can figure it out on your own now

what is the value of x

Answers

6^2 + 8^2 = x^2

36 + 64 = 100

sqrt(100) = 10

 x = 10

To solve this, we need to use Pythagorean Theorem. This is a formula that says a²+b²=c². A and B represent the legs of the triangle while c is the hypotenuse. We can simply substitute in our values for a and b and solve.

a²+b²=c²
8²+6²=c²
64+36=c²
100=c²
√100=√c²
10=c

Using the math above, we can see that c (x) equals 10.

What are the solutions to x2 8x 7 = 0? x = –8 and x = –7 x = –7 and x = –1 x = 1 and x = 7 x = 7 and x = 8?

Answers

We want to solve
x² + 8x + 7 = 0

Factorize the left side.
x² + 8x + 7 = (x + 1)(x + 7)

Therefore
(x + 1)(x + 7) = 0
When (x + 1) = 0, obtain x = -1.
When (x + 7) = 0, obtain x = -7.

The solutions are x = -1 and x = -7

Answer: x = -7  and x = -1.


The correct solutions to the given equation are x = 1 and x = 7.

The solutions to the equation x² - 8x + 7 = 0 are x = 1 and x = 7.

To find these solutions, we can factor the quadratic equation by finding two numbers that multiply to 7 (the constant term) and add up to -8 (the coefficient of the x term).

Therefore, the correct solutions to the given equation are x = 1 and x = 7.

How to write an equation with an undefined slope?

Answers

hello : 
an equation with an undefined slope is : x = a
parallal a : y axis

There are five position players on a starting basketball team: 2 guards, 2 forwards, 1 canter. Write a ratio in simplest from to express each relationship

Answers

Final answer:

The ratios for the basketball positions in simplest form are guards as 2:5, forwards as 2:5, and the center as 1:5.

Explanation:

The question asks to write ratios for the positions on a basketball team and then to express those ratios in simplest form. There are 5 position players on a starting basketball team, consisting of 2 guards, 2 forwards, and 1 center. To express the relationships between each position, we can write the ratios of guards to the total number of players, forwards to the total number of players, and the center to the total number of players.

The ratio of guards to the total number of players is 2 guards to 5 total players, which simplifies to 2:5.

The ratio of forwards to the total number of players is 2 forwards to 5 total players, simplifying to 2:5.

Lastly, the ratio of the center to the total number of players is 1 center to 5 total players, simplified as 1:5.

a customer brings in a item for refund.The price on the item is $4.80 and the tax is 5%.How much including tax should the cashier refund back to the customer

Answers

The entire amount will be the price multiplied by 1.05 (which is the price plus 5% of the price) This is 4.80 X 1.05= $5.04

Answer:

The cashier should refund back to the customer $5,04

Step-by-step explanation:

The cashier has to refund the amount the customer paid, which was the price plus the proportional tax.

Refund=price+tax

Price=$4.80

Tax=$4.80 * 0,05= $0,24

Refund=$4.80 +$0,24=$5,04

What is the solution to the following system of linear equations?

{4x - y = -6
{x - 2y = -5

Please explain how you solved!

Answers

Final answer:

The solution to the system of linear equations is x = -1, y = 2

Explanation:

To solve the system of linear equations:
4x - y = -6
x - 2y = -5
We can use the method of substitution or elimination to find the solution.
Let's use the elimination method. We can multiply the second equation by 4 to make the coefficients of x in both equations the same.
4(x - 2y) = 4(-5)
4x - 8y = -20
Now, we can subtract the second equation from the first equation to eliminate x.
(4x - y) - (4x - 8y) = (-6) - (-20)
-y + 8y = 14
7y = 14
y = 2
Substituting y = 2 back into the first equation:
4x - 2 = -6
4x = -4
x = -1
The solution to the system of linear equations is x = -1, y = 2

What is the multiplicative rate of change of the exponential function shown on the graph?

A) 2/9
B) 1
C) 4
D) 9/2

Answers

Answer:

Option: D is correct.

9/2

Step-by-step explanation:

We have to find the multiplicative rate of change of the exponential function shown on the graph.

We know that a general exponential function is given as:

[tex]y=ab^x[/tex]

where b is the multiplicative rate of change.

Now when x=0 we have y=1.

i.e. 1=a

Hence, a=1

and y=b^x

Also,

the graph passes through (1,9/2)

Now when x=1 we have y=9/2

i.e.

9/2=b

Hence, the multiplicative rate of change is:

9/2

The correct answer is A) 2/9. The multiplicative rate of change of the exponential function shown on the graph is A) 2/9.

To determine the multiplicative rate of change of an exponential function from its graph, we need to identify two points on the graph that are one unit apart horizontally (i.e., one unit apart in the x-direction). The multiplicative rate of change is the ratio of the function values (y-values) of these two points.

Let's assume we have two points, (x, y) and (x+1, y'), where y and y' are the corresponding y-values of the exponential function at these x-values. The multiplicative rate of change, r, is given by:

[tex]\[ r = \frac{y'}{y} \][/tex]

From the graph, we can identify two such points. For example, if the function passes through the y-axis at (0, 1) and then at (1, 2/9), we can calculate the multiplicative rate of change as follows:

[tex]\[ r = \frac{2/9}{1} = \frac{2}{9} \][/tex]

This is the multiplicative rate of change of the exponential function. It indicates that for every unit increase in x, the y-value is multiplied by 2/9.

Therefore, the multiplicative rate of change of the exponential function shown on the graph is A) 2/9.

A boy throws a baseball across a field. The ball reaches its maximum height, 18 meters, after 1 second. After approximately 2.3 seconds, the ball lands on the ground. The ball’s motion can be modeled using the function f(x) = –10x2 + 20x + 8. What is the height of the ball 1.5 seconds after it is thrown?

Answers

Answer:

Step-by-step explanation:

Alright, lets get started.

The function that models the height of the ball is given by :

[tex]f(x)=-10x^2+20x+8[/tex]

When we plug x as 1.5 , we could get the height f(1.5) as :

[tex]f(1.5)=-10(1.5)^2 +20*1.5 +8[/tex]

[tex]f(1.5)=-22.5+30+8[/tex]

[tex]f(1.5)=15.5[/tex]

So the height of the ball after 1.5 second is 15.5 meters.   : Answer

Hope it will help :)

Answer:

It is c on edge just took the test

Step-by-step explanation:

what is the measure of <DCF

Answers

129 degrees you just add DCE and ECF together

Answer:

The measure of angle DCF is 129 degrees.

Step-by-step explanation:

Angle DCF is the sum of angle DCE plus angle ECF.

This is because, DCF is the main angle and DCE and ECF are its two parts.

Hence, the measure of angle DCF will be = [tex]75+54=129[/tex] degrees.

The answer is :

The measure of angle DCF is 129 degrees.

Write each number as the product of its prime factors
1.) 76
2.) 35
3.)36
4.) 150
5.)180
6.) 520
please help i have 30 mins to get these answered!! :(

Answers

1) 2x2x3
2) 5x7
3) 2x2x3x3
4) 2x3x5x5
5) 2x2x3x3x5
6) 2x2x2x5x13

Need help please help

Answers

The vertex is (105,7)

Notice how on the graph, the y value peaks at 7. The y values to the left and right are symmetrical, meaning that the x value for the y value of 7 is the axis of symmetry, and the point (105,7) is the vertex.

What is the perimeter of a square with an area of 144 square inches?

Answers

Hi!

Since we know a square has sides of equal length, and to find the area of a square you square one of the side lengths, find the square root of 144.

The square root of 144 is 12.

So the means each side length is 12.

A perimeter is the distance around the square, or all of the side lengths added together.

4 sides on a square, each length is 12...
12 x 4 = 48

The perimeter is 48

Hope this helps! :)
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