chứng minh các hàm số sau là liên tục tại mọi điểm x thuộc R
a. f(x) = 6x+3
b. f(x) = mx+b
c. hãy nêu ý nghĩa của hàm liên tục trong kinh tế? trình bày một vài ví dụ minh họa

Answer:

1600

Step-by-step explanation:

multiply the volume value by 1000

Answer:

40 mi ^2

Step-by-step explanation:

SA = 2(lw+wh+lh)  where l is the length, w is the width, h is the height

SA = 2( 2*2 + 2*4 * 2*4)

    = 2( 4+8+8)

    = 2(20)

    = 40 mi ^2

Answer:

524cm^2

Step-by-step explanation:

Formula for Volume of sphere= 4/3 πr^2

We have,

r=5cm

Now,

Volume(v)=4/3 πr^2 = 4/3π 5^3= 4/3π 125 = 166.666666667π = 523.598775599

Rounding to the nearest tenth,

Volume=524cm^2

Answer:

3)x=0 y=1

Step-by-step explanation:

3) y=3x+1

    3x+y=1

    y=1-3x

1-3x=3x+1

1-1=3x+3x

0=6x

x=0

by substitute in 1

     y=3x+1

     y=3*0+1

     y=1

   5)  -5x+1=2x+4

         -5x-2x=4-1

         -7x=3

          x=-3/7

  by substitute in (y=2x+4)

            y=2*-3/7+4

              =25/7

Answer:

9^4 * 2^4

Step-by-step explanation:

We know (a*b) ^c = a^c * b^c

(9*2) ^4

9^4 * 2^4

Answer:

[tex]9^{4} * 2^{4}[/tex]

Step-by-step explanation:

rule:

[tex](a*b)^{c} = a^{c} * b^{c}[/tex]

distribute the exponent to both bases:

[tex]9^{4} * 2^{4}\\\\[/tex]

We are given the matrices A and B

[tex]A = \left[\begin{array}{ccc}2&3&-1\\0&2&5\\2&4&0\end{array}\right][/tex]

[tex]B = \left[\begin{array}{ccc}2\\1\\2\end{array}\right][/tex]

Multiplying these matrices:

We multiply matrices by taking the first column of the first matrix and the first row of the second matrix

we will multiply all the terms of the first column of the first matrix and multiply them by the terms of the first row of the second matrix, one by one

[tex]AB = \left[\begin{array}{ccc}2(2) + 3(1) + -1(2)\\0(2) + 2(1) + 5(2)\\2(2) + 4(1) + 0(2)\end{array}\right][/tex]

[tex]AB = \left[\begin{array}{ccc}5\\12\\8\end{array}\right][/tex]

9514 1404 393

Explanation:

Two matrices with dimensions (numbers of (rows, columns)) of (a, b) and (c, d) can only be multiplied if the number of columns in the left matrix is equal to the number of rows in the right matrix. That is, b=c. The dimensions of the product matrix will be (a, d).

For row i of the left matrix and column j of the right matrix, element a(i,j) of the product matrix is the dot-product of row i with column j. (The dot-product of two vectors is the sum of the products of corresponding elements.)

__

The example matrices have (row, column) dimensions (3, 3) and (3, 1), so can be multiplied with a result having dimensions (3, 1).

It is useful to refer to an element of a matrix by specifying the row and column in which it resides. An element of matrix 'A' in row 2 and column 3 can be referred to as A(2,3). Often, subscripts are used, as in ...

  [tex]A_{i,j}[/tex]

For matrix C = A·B, the element C(1,1) will be the sum ...

  A(1,1)B(1,1) +A(1,2)B(2,1) +A(1,3)B(3,1)

Calculators, apps, spreadsheets, and web sites are available that will perform this arithmetic for you. It can be a bit tedious to do by hand.

Here the product is ...

  [tex]A\cdot B=\left[\begin{array}{ccc}2&3&-1\\0&2&5\\2&4&0\end{array}\right] \cdot\left[\begin{array}{c}2&1&2\end{array}\right] =\left[\begin{array}{c}2(2)+3(1)+(-1)(2)&0(2)+2(1)+5(2)&2(2)+4(1)+0(2)\end{array}\right] \\\\=\left[\begin{array}{c}5&12&8\end{array}\right][/tex]

Answer:

x=9

Step-by-step explanation:

-4x-3=-x-30

-4x+x=-30+3

-3x=-27

x=9

Answer:

1. 1.66in

2. 6.66in

3. 3.33in

4. 1inch

Step-by-step explanation:

the area of a rectangle is found by multiplying the length times width or the two sides.

5 x 1/3 is about 1.66 inches

5 x 4/3 is about 6.66 inches

5/2 x 4/3 is about 3.33 inches

and 7/6 x 6/7 is 1 inch

Answer:

32.70

Step-by-step explanation:

round up

Answer:

this answer requires that you do a little solving to find all the dimensions we need for the volume.

We know that H (height) = 2m

Diameter = 5 x height, so

Diameter = 5 x 2m = 10m

If you have the formula for finding the volume of a cylinder, it is basically the area of the circular base x cylinder height. You may know already that the area of a circle is (pi) x radius2

So this will be 2 (the height) x (pi) x r2

As we just figured out, the DIAMETER is 10, so the radius is half the diameter = 5.

This brings our volume to 2 x (pi) x 52

= 2 x (pi) x 25

2x25 = 50, so we have 50 x (pi).

Pi = 3.14

50 x 3.14 = 157

And don't forget your units = 157 m3

Answer:

Step-by-step explanation:

the probability that the test result is positive (suggesting the person has the disease), given that the person does not have the disease, is only 2 percent; the probability that the test result is negative (suggesting the person does not have the disease), given that the person has the disease, is only 1 percent.

Answer:

-12

Step-by-step explanation:

√50-3√2(2√2-5) -5√32​

= 5√2 -12+15√2-5(4)√2

= 5√2 -12+15√2-20√2

= -12

Answer:

A = 123

B = 39

C = 379

Step-by-step explanation:

If 569 freshmen like at least one of these 3 types os music, it means that the sum of the numbers inside the 3 circles have to be 569, and it also means that the difference between these freshmen (those inside the 3 circles) and the total freshmen surveyed don't like any of these type of music, so:

692 – 569 = 123 freshmen that don't like these 3 types of music, and this is the slot A

Now, for the slot B, we have to sum all the numbers inside the circles and see how much left to be equal to 569 (the total of freshmen that like at least one of the 3 type of music):

87 + 106 + 63 + 163 + 87 + 24 + B = 569

530 + B = 569

B = 569 – 530

B = 39

And now, the slot C is the number of freshman that don't like rock, so we have to sum all the numbers outside the circle purple:

87 + 106 + 63 + A = C

We know that A = 123, so:

C = 87 + 106 + 63 + 123

C = 379

9514 1404 393

Answer:

  a) 2

  b) left: 3; lower right: 5

  c) upper right: 53°; bottom: 82°

Step-by-step explanation:

a) The top side of polygon B is 5 units; the corresponding top side of polygon A is 2.5 units, so the dimensions of polygon A are multiplied by the scale factor 5/2.5 = 2 to give the dimensions of polygon B.

  the scale factor is 2

__

b) Sides of polygon B are 2 times the length of the corresponding side of polygon A.

  left side: 2×1.5 = 3

  lower right side: 2×2.5 = 5

__

c) Corresponding angles of similar figures are congruent.

  upper right angle: 53°

  bottom angle: 82°

___

4.

The arithmetic of problem 4 is correct as shown.

Answer:

it is  D.

Step-by-step explanation:

Answer:

See below

Step-by-step explanation:

we want to prove that A.M, G.M. and H.M between any two unequal positive numbers satisfy the following relations.

well, to do so let the two unequal positive numbers be [tex]\text{$x_1$ and $x_2$}[/tex] where:

the AM,GM and HM of [tex]x_1[/tex] and[tex] x_2[/tex] is given by the following table:

[tex]\begin{array}{ |c |c|c | } \hline AM& GM& HM\\ \hline \dfrac{x_{1} + x_{2}}{2} & \sqrt{x_{1} x_{2}} & \dfrac{2}{ \frac{1}{x_{1} } + \frac{1}{x_{2}} } \\ \hline\end{array}[/tex]

[tex] \displaystyle \rm AM \times HM = \frac{x_{1} + x_{2}}{2} \times \frac{2}{ \frac{1}{x_{1} } + \frac{1}{x_{2}} } [/tex]

simplify addition:

[tex] \displaystyle \frac{x_{1} + x_{2}}{2} \times \frac{2}{ \dfrac{x_{1} + x_{2}}{x_{1} x_{2}} } [/tex]

reduce fraction:

[tex] \displaystyle x_{1} + x_{2} \times \frac{1}{ \dfrac{x_{1} + x_{2}}{x_{1} x_{2}} } [/tex]

simplify complex fraction:

[tex] \displaystyle x_{1} + x_{2} \times \frac{x_{1} x_{2}}{x_{1} + x_{2}} [/tex]

reduce fraction:

[tex] \displaystyle x_{1} x_{2}[/tex]

rewrite:

[tex] \displaystyle (\sqrt{x_{1} x_{2}} {)}^{2} [/tex]

[tex] \displaystyle AM \times HM = (GM{)}^{2} [/tex]

hence, PROVEN

[tex] \displaystyle x_{1} > x_{2}[/tex]

square root both sides:

[tex] \displaystyle \sqrt{x_{1} }> \sqrt{ x_{2}}[/tex]

isolate right hand side expression to left hand side and change its sign:

[tex]\displaystyle\sqrt{x_{1} } - \sqrt{ x_{2}} > 0[/tex]

square both sides:

[tex]\displaystyle(\sqrt{x_{1} } - \sqrt{ x_{2}} {)}^{2} > 0[/tex]

expand using (a-b)²=a²-2ab+b²:

[tex]\displaystyle x_{1} -2\sqrt{x_{1} }\sqrt{ x_{2}} + x_{2} > 0[/tex]

move -2√x_1√x_2 to right hand side and change its sign:

[tex]\displaystyle x_{1} + x_{2} > 2 \sqrt{x_{1} } \sqrt{ x_{2}}[/tex]

divide both sides by 2:

[tex]\displaystyle \frac{x_{1} + x_{2}}{2} > \sqrt{x_{1} x_{2}}[/tex]

[tex]\displaystyle \boxed{ AM>GM}[/tex]

again,

[tex]\displaystyle \bigg( \frac{1}{\sqrt{x_{1} }} - \frac{1}{\sqrt{ x_{2}}} { \bigg)}^{2} > 0[/tex]

expand:

[tex]\displaystyle \frac{1}{x_{1}} - \frac{2}{\sqrt{x_{1} x_{2}} } + \frac{1}{x_{2} }> 0[/tex]

move the middle expression to right hand side and change its sign:

[tex]\displaystyle \frac{1}{x_{1}} + \frac{1}{x_{2} }> \frac{2}{\sqrt{x_{1} x_{2}} }[/tex]

[tex]\displaystyle \frac{\frac{1}{x_{1}} + \frac{1}{x_{2} }}{2}> \frac{1}{\sqrt{x_{1} x_{2}} }[/tex]

[tex]\displaystyle \rm \frac{1}{ HM} > \frac{1}{GM} [/tex]

cross multiplication:

[tex]\displaystyle \rm \boxed{ GM >HM}[/tex]

hence,

[tex]\displaystyle \rm A.M>G.M>H.M[/tex]

PROVEN

Answer:

RS 17.10

Step-by-step explanation:

If they earn 0.95 a day, you can multiply that income by the number of days, which is 18.

RS 17.10

Answer:

785.4

I think it is right

Answer:

Solution: Here, Radius of cylindrical tank (r)=2ml Height of cylindrical tank (h)=8ml volume of that cylindrical tank (v)=?

Now,

we know that,

Volume of cylindrical(v)=V=πr2h=3.14×2×2×8=100.48ans.

Answer:

so your answer is (0.5,-1)

Answer:

Step-by-step explanation:

It is unclear from the phrasing what dimension 8.2 ft represents.

If 8.2 ft is the direct distance from the edge of the roof to the top of the pitch, then the horizontal distance from the edge to the top is √(8.2²-2.4²) ≅ 7.84 ft, and the slope is 2.4/7.84 ≅ 0.31

If 8.2 ft is the horizontal distance from the edge of the root to the top of the pitch, then the slope is 2.4/8.2 ≅ 0.29

The slope of a roof on a house is 0.2926 and the angle of elevation is 16.31°.

The slope or gradient of a line is a number that describes both the direction X and Y and the steepness of the line. It is the ratio of the vertical change to the horizontal change between any two distinct points on a line.

For the given situation,

The diagram below shows the house with the roof.

The vertical height of roof on a house, rise = 2.4 feet

The horizontal length of a roof on a house, run = 8.2 feet

The slope of a roof can be found as

[tex]Slope = \frac{rise}{run}[/tex]

⇒ [tex]slope = (\frac{2.4}{8.2} )[/tex]

⇒ [tex]slope = 0.2926[/tex]

The angle of the slope of a roof can be found as

[tex]tan \alpha =\frac{vertical height}{horizontal length}[/tex]

⇒ [tex]\alpha =tan^{-1} (\frac{2.4}{8.2} )[/tex]

⇒ [tex]\alpha =tan^{-1} (0.2926)[/tex]

⇒ [tex]\alpha =16.31[/tex]

Hence we can conclude that the slope of a roof on a house is 0.2926 and the angle of elevation is 16.31°.

Learn more about slope of a line here

https://brainly.com/question/6204743

#SPJ2

Answer:

15/8

Step-by-step explanation:

tan(62)=P/B

tan(62)=15/8

Answer:

A. x < -3 or x > -3

Step-by-step explanation:

Let's start with the equation -4x + 60 < 72.

-4x + 60 < 72

First using the order of operations, subtract 60 from both sides.

-4x + 60 - 60 < 72 - 60

- 4x < 12

Next we want to divide -4 from both sides to isolate the variable.

-4x/-4 < 12/-4

x > -3

When you divide a negative number, always make sure the change the sign.

Solve the next equation, 14x + 11 < -31, the same way we solved the last.

14x + 11 < -31

Subtract 11 from both sides.

14x + 11 - 11 < -31 -11

14x < -42

Divide 14 from both sides.

14x/14 < -42/14

x < -3

The equations have different signs.

A. x < -3 or x > -3

Answer:

Answer: negative

Y= -500x + 4,500

Step-by-step explanation:

Answer:

C. negative

B. Y= -500x + 4,500

I just did it

Step-by-step explanation:

The graph clearly has a positive slope. So Answer D couldn't be correct. Next: the y-intercept of this line is (0, -2), so b in the formula y = mx÷ b must be -2.

Therefore the correct equation of this line is

y = x - 2 (choice a)

A quotient is found by dividing two numbers and a quotient with a denominator of zero is infinity which is not a real number

The word that complete the sentence is therefore;

Each quotient must have a nonzero denominator

The reason by which the above word is selected is as follows;

The set of Real Numbers include;

Rational numbers; a/b, where b = nonzero number

Integers; Positive and negative whole numbers, including zero

Whole numbers; 0, 1, 2

Natural numbers; Positive whole numbers excluding zero

Irrational number; Numbers that cannot be expressed as a/b

A quotient is the outcome of dividing two numbers, x by y

Therefore;

Quotient = x/y

A quotient can be a rational or irrational number, however, a quotient that has a denominator of zero (y = 0) is infinity, which is not a real number

When y = 0, x/y = x/0 = ∞ (∞ is not a real number)

Therefore, from the properties of Real Numbers,

Each quotient must have a nonzero denominator to be a Real Number

Learn more about Real Numbers here;

https://brainly.com/question/11030818

Answer:

30÷4

Step-by-step explanation:

Answer:

Hello,

in order to simplify, i have taken the inverses functions

Step-by-step explanation:

[tex]\int\limits^\frac{1}{2} _{-1} {(-2x^2-x+1)} \, dx \\\\=[\frac{-2x^3}{3} -\frac{x^2}{2} +x]^\frac{1}{2} _{-1}\\\\\\=\dfrac{-2-3+12}{24} -\dfrac{-5}{6} \\\\\boxed{=\dfrac{9}{8} =1.25}\\[/tex]

Answer: 205.3

I suppose all measures of angles are done from the same axis (for example x-axis)

Step-by-step explanation:

You just have to use the theorem of Al'Kashi:

[tex]d^2=400^2+300^2-2*300*400*cos(30^o)\\\\d\approx{205.3(km)}[/tex]

Answer:

I'm not 100% on the interoperation of this question...

are the two red cars out of a 52 card deck and you can try all the combinations of two red and black cards ????

for this answer i will assume that you have 4 coins two nickels and 2 quarters

and the question is " how many ways can you arrange the four coins given that the nickels can not be next to the quarters"

in that case I think the answer is 8

Step-by-step explanation:

1- N1 Q1 N2 Q2

2- N1 Q2 N2 Q1

3- N2 Q1 N1 Q2

4- N2 Q2 N1 Q1

5- Q1 N2 Q2 N1

6- Q2 N2 Q1 N1

7- Q1 N1 Q2 N2

8- Q2 N1 Q1 N2

[tex]2\cdot \left(\left(2\:choose\:1\right)\:\cdot \:\left(2\:choose\:1\right)\right)[/tex]

Answer:

64

Step-by-step explanation:

The Ratio of Blue to White drops is 2:8

16*4=64,... 16:64 Have a nice day!