cho tứ giác ABCD. Gọi M,N,P,Q là trung điểm của các cạnh AB, CD, AD, BC. Chứng minh rằng vecto MP = vecto QN, vecto MQ = vecto PN

Answers

Answer 1

Answer:

Step-by-step explanation:

Xét tam giác DAB có: P là trung điểm AD, M là trung điểm AB

=> MP là đường trung bình của tam giác DAB => MP//BD và MP=[tex]\frac{1}{2}[/tex]BD  (1)

Xét tam giác DBC có: N là trung điểm DC, Q là trung điểm BC

=> QN là đường trung bình của tam giác DBC => QN//BD và QN=[tex]\frac{1}{2}[/tex]BD  (2)

Từ (1) và (2) => vecto MP song song cùng chiều với vecto QN

và độ dài MP = độ dài QN = [tex]\frac{1}{2}[/tex]BD

=> vecto MP = vecto QN

Tương tự xét các tam giác DAC và tam giác ABC => vecto MQ = vecto PN


Related Questions

PLEASE HELP AND EXPLAIN!!

Answers

Answer:

D

Step-by-step explanation:

This isnt a cartisean coordinate plane so A is wrong. One of our points is at

[tex] - 3 + i[/tex]

Because it coincide with real number 3, and negative imaginary number i.

Conjugates are terms with opposite inverse of terms.

So our conjugates is

[tex] - 3 - i[/tex]

The velocity of a bus increases from 72km/hr to 30m/s in 10 seconds. Calculate its acceleration

Answers

Answer:

I think this will help you

i need help with this

Answers

Answer:

A) (-8, -16)

B) (0, 48)

C) (-4, 0), (-12, 0)

Step-by-step explanation:

A) the vertex is the minimum y value.

extremes of a function we get by using the first derivation and solving it for y' = 0.

y = x² + 16x + 48

y' = 2x + 16 = 0

2x = -16

x = -8

so, the vertex is at x=-8.

the y value is (-8)² + 16(-8) + 48 = 64 - 128 + 48 = -16

B) is totally simple. it is f(0) or x=0. so, y is 48.

C) is the solution of the equation for y = 0.

the solution for such a quadratic equation is

x = (-b ± sqrt(b² - 4ac)) / (2a)

in our case here

a=1

b=16

c=48

x = (-16 ± sqrt(16² - 4×48)) / 2 = (-16 ± sqrt(256-192)) / 2 =

= (-16 ± sqrt(64)) / 2 = (-16 ± 8) / 2 = (-8 ± 4)

x1 = -8 + 4 = -4

x2 = -8 - 4 = -12

so the x- intercepts are (-4, 0), (-12, 0)

In figure above, if l1 | | l2 then value of x is:
a) 40°
b) 50°
c) 80°
d) 100°

Answers

Answer:

its letter c so 80

Step-by-step explanation:

I hope this help

The sine of angle θ is 0.3.

What is cos(θ)? Explain how you know.

Answers

Answer:

cos(θ) = -0.95

Step-by-step explanation:

Remember the relation:

sin(θ)^2 + cos(θ)^2 = 1

So if we have:

sin(θ) = 0.3

we can replace that in the above equation to get:

0.3^2 + cos(θ)^2 = 1

now we can solve this for cos(θ)

cos(θ)^2 = 1 - 0.3^2 = 0.91

cos(θ) = ±√0.91

cos(θ) = ± 0.95

Now, yo can see that there are two solutions, which one is the correct one?

Well, you can see that the endpoint of the segment that defines θ is on the second quadrant.

cos(x) is negative if the endpoint of the segment that defines the angle is on the second or third quadrant.

Then we can conclude that in this case, the correct solution is the negative one.

cos(θ) = -0.95

Find the measure of each angle indicated.
A) 95°
C) 26°
B) 92°
D) 20°

Answers

Answer:

D) 20°

Step-by-step explanation:

Using the triangle sum theorem, you know that every triangle's interior angles add up to 180°. Therefore the bottom triangle's missing angle can be found by giving it the variable x.

57° + 30° + x = 180°

Simplify: 87° + x =180°

x=93°

By the vertical angles theorem, the vertical angle directly across this angle is congruent to this one. Meaning that the top triangle's angle are 67°, 93°, and unknown, which we can assign y. We can use the same method from above here.

67° + 93° + y = 180°

Simplify: 160° + y = 180°

y=20°

Answer:

(C). 26°

Step-by-step explanation:

Maritza is comparing cell phones plans and notices that verizon offers a plan that is $60 for 10GB of data and $12 for each extra GB of data ore month. Create an expression to model this situation

Answers

Answer:

60 + 12 * g, with g representing the number of extra gigabytes

Step-by-step explanation:

First, we know that Maritza has to pay $60 for 10GB of data, no matter what. Therefore, the base cost of the cell phone plan is 60 dollars, and all extra costs must be added to that. Currently, our expression is therefore 60 + something = cost of cell phone plan.

After that, the plan costs $12 for each gigabyte of data past 10 GB. This means that, for example, if Maritza uses 11 gigabytes, the plan will cost 60 (the base amount) + 12 for each gigabyte past 10 GB. There are 11-10=1 extra gigabytes, so the cost is 60 + 12 * 1 = 72 dollars. For each extra gigabyte, 12 dollars are added, so we can represent this as

60 + 12 * g, with g representing the number of extra gigabytes

after allowing 20% discount an article is sold for rs.672 levying 12% VAT, find its market price​

Answers

The market price is Rs. 750 which was obtained by creating a mathematical relationship from the given parameters.

PERCENTAGE DISCOUNT = 20%

VAT LEVIED= 12%

PRICE SOLD = 672

Let the MARKET PRICE = m

Hence,

market price * (1 - discount) * (1 + VAT) = price sold

m * (1 - 20%) * (1 + 12%) = 672

m * (1 - 0.2) * (1 + 0.12) = 672

m * 0.8 * 1.12 = 672

0.896m = 672

m = 672 / 0.896

m = Rs. 750

Learn more :

https://brainly.com/question/20418815

The Market Price of the product is RS. 750.

The Market Price is calculated by dividing the components associated to Discount, which is less than 1, and the Value Added Tax, which more than 1, to the Resulting Price.

[tex]c_{M} = \frac{c_{R}}{\left(1-\frac{r_{D}}{100} \right)\cdot \left(1+\frac{r_{T}}{100} \right)}[/tex] (1)

Where:

[tex]c_{M}[/tex] - Market price, in monetary units.

[tex]c_{R}[/tex] - Resulting price, in monetary units.

[tex]r_{D}[/tex] - Discount rate, in percentage.

[tex]r_{T}[/tex] - Tax rate, in percentage.

If we know that [tex]c_{R} = 672[/tex], [tex]r_{D} = 20[/tex] and [tex]r_{T} = 12[/tex], then the market price is:

[tex]c_{M} = \frac{672}{\left(1-\frac{20}{100} \right)\cdot \left(1+\frac{12}{100} \right)}[/tex]

[tex]c_{M} = 750[/tex]

The market price of the product is RS. 750.

solve for x.
solve for x.
solve for x.

Answers

Answer:

[tex]x=10[/tex]

Step-by-step explanation:

A secant is a line segment that intersects a circle in two places. One property of a secant is the product of the lengths ratio. This ratio can be described as the following, let ([tex]inside[/tex]) refer to the part of the secant that is inside the circle, and ([tex]outside[/tex]) refer to the part that is outside of it. ([tex]total[/tex]) will refer to the entirety of the secant or ([tex]inside+outside[/tex]). The numbers (1) and (2) will be used as subscripts to indicate that there are two different secants.

[tex](outside_1)(total_2)=(outside_2)(total_2)[/tex]

Substitute,

[tex](outside_1)(total_2)=(outside_2)(total_2)[/tex]

[tex](outside_1)(inside_1+outisde_1)=(outside_2)(inside_2+outside_2)[/tex]

[tex](6)(6+x+5)=(7)(7+x+1)[/tex]

Simplify,

[tex](6)(6+x+5)=(7)(7+x+1)[/tex]

[tex]6(x+11)=7(x+8)[/tex]

[tex]6x+66=7x+56[/tex]

Inverse operations,

[tex]6x+66=7x+56[/tex]

[tex]66=x+56[/tex]

[tex]10=x[/tex]

evaluate : 8/-5+(4/-3)+1/3

Explain full steps
with easy method​

Answers

Answer:

-39/15

Step-by-step explanation:

=-8/5-4/3+1/3

Taking LCM of 5,3 and 3.

=3(-8)-5(4)+5(1)/15

=-24-20+5/15

=-44+5/15

=-39/15

Note:if you need to ask any question please let me know.

mutual sold an item for sh.3250 after allowing his customers a 12% discount on the marked price.if he had sold the article without giving a discount,he would have made a profit of 25%.calculate the percentage profit he made by selling the article at a discount?​

Answers

Answer:

lol Step-by-step explanation:

What is the length of the hypotenuse in the triangle below?
A right triangle is shown. 2 sides have lengths of 14 centimeters. The length of the hypotenuse is unknown.
a. 14 cm
b. 14 StartRoot 2 EndRoot cm
c. 14 StartRoot 3 EndRoot cm
d. 28 cm

Answers

Answer:

B

Step-by-step explanation:

Hypotenuse=sqrt(Side^2+side^2)=sqrt(14^2+14^2)=14*sqrt(2)

Answer:  

B  

Step-by-step explanation:  

Hypotenuse=sqrt(Side^2+side^2)=sqrt(14^2+14^2)=14*sqrt(2)

is 9y+3=0 a nonlinear ?

Answers

Answer:

Its not nonlinear

Step-by-step explanation:

Answer:

no, it is a linear function as y has a degree of 1

Hello, have anyone can help me to solve this question?

Answers

Answer:

24 days LCM

prime factor :

4- 2, 2

8-2,2,2

12- 2,2,3

largest factors- 2,2,2,3

2*2*2*3 = 24

Step-by-step explanation:

FIRST ANSWER GETS BRAINLIEST!!
(sorry for the colors on the picture)

Answers

It is the 3rd answer

Its 3rd……! obviously

The area under the standard normal curve to the right of z = -0.51 is 0.6950. What is the area to the left of z = 0.51?

Answers

Answer:

0.305

Step-by-step explanation:

We are told that area under the standard normal curve to the right of z = -0.51 is 0.6950

Thus, to get the area to the left, we just subtract 0.6950 from 1.

Thus;

area to the left of z = 0.51 is;

P( z < 0.51) = 1 - 0.6950 = 0.305

Estimate 3 divided by 1788

Answers

Answer:

Maybe the answer for ur question is 1/596 if the 3 divides the number if not then it's only 596

find the distance traveled in 27.9 minutes

Answers

Answer:

A

Step-by-step explanation:

d = 0.5 * t    There are no conversions. You just substitute the value for t.

d = 0.5 * 27.9

d = 13.95 which is A

the vertex of this parabola is at (-2 -3). When the y value is -2, the x value is -5. What is the coefficient of the squared term in the parabolas equation.

Answers

Answer:

1/9

Step-by-step explanation:

The vertex form is

y =a(x-h)^2 +k where (h,k) is the vertex

The vertex is (-2,-3)

y =a(x--2)^2 +-3

y =a(x+2)^2 -3

Substitute the point into the equation

-2 = a(-5+2)^2 -3

-2=a(-3)^2-3

Add 3 to each side

-2+3 = a(9)

1 = 9a

1/9 =a

y =1/9(x+2)^2 -3

The coefficient of the x^2 is 1/9

Answer:

[tex]\frac{1}{9}[/tex]

Step-by-step explanation:

The equation of a parabola in vertex form is

y = a(x - h)² + k

where (h, k) are the coordinates of the vertex and a is a multiplier

Here (h, k ) = (- 2, - 3) , then

y = a(x + 2)² - 3

To find a substitute (- 5, - 2 ) into the equation

- 2 = a(- 5 + 3)² - 3 ( add 3 to both sides )

1 = a(- 3)² = 9a ( divide both sides by 9 )

[tex]\frac{1}{9}[/tex] = a

y = [tex]\frac{1}{9}[/tex] (x + 2)² - 3

The coefficient of the x² term is therefore [tex]\frac{1}{9}[/tex]

Geometry, please answer question ASAP

Answers

Answer:

C) 81 degrees

Step-by-step explanation:

all quadrilateral's sum of interiror angles is 360 degrees

right angles are 90 degrees

call measure of angle C =y

360=90+90+99+y

180=99+y

y= 81

I need help please I don't understand

Answers

Answer:

57.2

Step-by-step explanation:

This is a right triangle so we can use trig ratios.

We are asked to find a side when we know a angle adjacent to that side. And we are given a side opposite of that angle. We can use Tangent to find the side length.

[tex] \tan(40) = \frac{48}{x} [/tex]

Take the reciprocal of both sides.

[tex] \frac{1}{ \tan( 40) ) } = \frac{x}{ 48} [/tex]

Multiply both sides by 48.

[tex] x = \frac{1}{ \tan(40) } \times 48[/tex]

[tex]x = 57.2[/tex]

An office was built in the shape of a rectangle. If one side of the office measures 60 metres and the length is measured 4000 centimetres.

Calculate the perimeter of the office in meters.

Answers

Answer:

200m

Step-by-step explanation:

Width=60m

Length=4000cm=40m

[PERIMETER OF RECTANGLE= 2(l+b)]

2(40+60)

2×100

200cm

The function f(t) = 4t2 − 8t + 7 shows the height from the ground f(t), in meters, of a roller coaster car at different times t. Write f(t) in the vertex form a(x − h)2 + k, where a, h, and k are integers, and interpret the vertex of f(t).

A) f(t) = 4(t − 1)2 + 3; the minimum height of the roller coaster is 3 meters from the ground
B) f(t) = 4(t − 1)2 + 3; the minimum height of the roller coaster is 1 meter from the ground
C) f(t) = 4(t − 1)2 + 2; the minimum height of the roller coaster is 2 meters from the ground
D) f(t) = 4(t − 1)2 + 2; the minimum height of the roller coaster is 1 meter from the ground

Answers

Answer:

A) f(t) = 4(t − 1)^2 + 3; the minimum height of the roller coaster is 3 meters from the ground

Step-by-step explanation:

f(t) = 4t^2 − 8t + 7

Factor out 4 from the first two terms

f(t) = 4(t^2 − 2t) + 7

Complete the square

(-2/2)^2 =1  But there is a 4 out front so we add 4 and then subtract 4 to balance

f(t) = 4( t^2 -2t+1) -4 +7

f(t) = 4( t-1)^2 +3

The vertex is (1,3)

This is the minimum since a>0

The minimun is y =3 and occurs at t =1

Answer:

The above answer is correct.

Step-by-step explanation:

Given: PSTK is a rectangle
Area of PSTK=562m^2
m∠TOK=75
Find:PS, PK
(HELP! ILL GIVE BRAINLIEST)

Answers

Answer:

See picture below

Step-by-step explanation:

Let PK be the length and PS be the width of the rectangle.

Then LW =562

Assuming O is the center of the rectangle then ∠KST = ∠STO = 75/2

Hence tan ( 75/2 ) = PS/PK

Now solve the system of the equations

PS*PK=562

tan ( 75/2 ) = PS/ PK

Find the length of each segment.
W X
Y
--5
0
5
5. WX
6. WY

Answers

WX is 2 WY is 9 because each time it moves it’s moving 1 time

The length of the line segments WX and XY will be 2 and 9, resprectively.

What is a line segment?

A line segment in mathematics has two different points on it that define its boundaries. A line segment is sometimes referred to as a section of a path that joins two places.

The three points are W, X, and Y on the line.

From the diagram, the distance between the points W and X which is the line segment WX will be 2.

Similarly, from the diagram, the distance between the points W and Y which is the line segment WY will be 9.

More about the line segment link is given below.

https://brainly.com/question/25727583

#SPJ2

Whats 5867 times 382?

Answers

Whats 5867 times 382?

answer;

5867×382

=2241194

Hope it helps you.........

State the transformations on the graph of f(x) = ^ x that result in the graph of the given functions.
Write the transformation rule.

Answers

The answer is 9/10 because I did the test and that was the answer

(x-3).(x+3)-(x+5).(x-1)

Answers

is the dot a multiplication sign? if so the answer is -4x-4 (simplified)
bất đẳng thức đáng nhớ rồi phá cái bên cạnh ra là dc

A new car that is a gas- and electric-powered hybrid has recently hit the market. The distance traveled on 1 gallon of fuel is normally distributed with a mean of 65 miles and a standard deviation of 7 miles. Find the probability of the following events: a. The car travels more than 69 miles per gallon. Proba

Answers

Answer:

0.28386

Step-by-step explanation:

Given that :

Mean, μ = 65 miles

Standard deviation, σ = 7 miles

Probability that car travels more than 69 miles per gallon :

Recall,

Z = (x - μ) / σ ; x = 69

Z = (69 - 65) / 7 = 0.5714

The probability :

P(Z > z) = P(Z > 0.5714) = 1 - P(Z < 0.5714)

P(Z > 0.5714) = 1 - P(Z < 0.5714) = 1 - 0.71614 = 0.28386

P(Z > 0.5714) = 0.28386

Solve for X. Geometry

Answers

Answer:

x=12

Step-by-step explanation:

LM + MN = LN

2x-16 + x-9 = 11

Combine like terms

3x-25=11

Add 25 to each side

3x-25+25 = 11+25

3x = 36

Divide by 3

3x/3=36/3

x = 12

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