Given that f(x) = x2 – 3x – 28 and g(x) = x - 7, find
(f - g)(x) and express the result in standard form.

Answers

Answer 1

Answer:

[tex](f-g)(x)=x^2-4x-21[/tex]

Step-by-step explanation:

We are given the two functions:

[tex]f(x)=x^2-3x-28\text{ and } g(x)=x-7[/tex]

And we want to find:

[tex](f-g)(x)[/tex]

This is equivalent to:

[tex]=f(x)-g(x)[/tex]

Substitute:

[tex]=(x^2-3x-28)-(x-7)[/tex]

Distribute:

[tex]=x^2-3x-28-x+7[/tex]

Rearrange:

[tex]=(x^2)+(-3x-x)+(-28+7)[/tex]

Hence:

[tex](f-g)(x)=x^2-4x-21[/tex]


Related Questions

Evaluate the function.
f(x) = 2x2
Find f(-3)

Can anybody answer this?

Answers

Answer:

18

Step-by-step explanation:

f(x) = 2x^2

Let x = -3

f(-3) = 2 * (-3)^2

Exponents first

f(-3)=2 *9

f(3) = 18

Answer:

f ( - 3 ) = 18

Step-by-step explanation:

f ( x ) = 2x²

Find f ( - 3)

let , x = - 3

lf ( - 3 ) = 2 ( -3 )²

f ( - 3 ) = 2 × ( - 3 )²

Evaluate the power

f ( -3) = 2 × 9

multiply the numbers

f ( - 3 ) = 18

Which of the following expressions are equivalent to 52n+n4n2 + 4n
5
2
n
+
n
4
n
2

+

4
n
?

Answers

Answer:

they just go straight what does it mean?

PLEASSSSSSSSSSSEEEEEEEE HELPPP IM BEGGING SOMEONE PLEASEEEEEEEE PLEASEEEEEEEEEEE HELPPPP​

Answers

Answer:

20 degree

Step-by-step explanation:

x + x + 70 = 110 degree (sum of two opposite interior angle equal to the exterior angle formed)

2x = 110 - 70

x = 40/2

x = 20 degree

The party planning committee has to determine the number of tables needed for an upcoming event. If a square table can fit 8 people and a round table can fit 6 people, the equation 150 = 8x + 6y represents the number of each type of table needed for 150 people.


The variable x represents the number of

Answers

Answer:

Square tables used

Step-by-step explanation:

x represents the number of square tables used since it is being multiplied times 8 which is the number of people a square table can fit

Answer:

answer in pictures

Step-by-step explanation:

Charlie (c) has 75 more pencils than Kate (k). Together, they have 135 pencils. How many pencils does Kate have? * ​

Answers

Answer:

60

Step-by-step explanation:

135-75 = 60

HOPE IT HELPS

The net of a solid figure is shown below:
Which calculation will give the total surface area of the solid figure? (1 point)

1) 5.6.6 square inches
2) 6.5.5 square inches
3) 6.5.5.5 square inches
4) 5.6.6.6 square inches

Answers

Answer:  6*5*5   (choice B)

===========================================================

Explanation:

Each square has a side length of 5 inches, so each square has area 5*5 = 25 square inches. We have 6 such squares to give a total surface area of 6*25 = 150 square inches.

Effectively, this is the same as using the formula below

S = 6x^2

S = 6*5^2

S = 6*5*5

S = 150

x = 5 refers to the side length and S is the surface area. It might help to cut the figure from the paper, and fold it up and you should find that a 3D box will form. There are 6 faces with area of 5*5 each, hence the 6*5*5

The following hypothetical data represent a sample of the annual numbers of home fires started by candles for the past several years.
5640, 5090, 6590, 6380, 7165, 8440, 9980
The population has a standard deviation equal to 1210. Assuming that the data is from a distribution that is approximately normal, construct a 90 % confidence interval for the mean number of home fires started by candles each year

Answers

Answer:

(6290.678 ; 7790.742)

Step-by-step explanation:

Given the data :

5640, 5090, 6590, 6380, 7165, 8440, 9980

The sample mean, xbar = Σx / n = 49285 / 7 = 7040.71

The 90% confidence interval :

Xbar ± Margin of error

Margin of Error = Zcritical * σ/√n

Since the σ is known, we use the z- distribution

Zcritical at 90% confidence = 1.64

Hence,

Margin of Error = 1.64 * 1210/√7

Margin of Error = 750.032

90% confidence interval is :

7040.71 ± 750.032

Lower boundary = 7040.71 - 750.032 = 6290.678

Upper boundary = 7040.71 + 750.032 = 7790.742

(6290.678 ; 7790.742)

A bag has 2 yellow marbles and 16 red marbles. Half of the red marbles are made of plastic. A marble is selected at random from the ball What is the probability that it is a red, plastic marble? Write your answer as a fraction in simplest form. ​

Answers

Answer:

4/9

Step-by-step explanation:

2+16 = 18 total marbles

16 ÷ 2= 8 plastic marbles

Since there are 18 total marbles and 8 plastic red marbles we can say that there is a probability of 8/18.

8/18 in simplest form is 4/9.

Hope this helps! Brainliest?

4. What is the product of (3x - 1)(x + 4)?
HELP PLEASE RIGHT NOT SHOW YOURE WORK!!!!!

Answers

[tex]3 {x}^{2} + 11x - 4[/tex]

[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\orange{:}}}}}[/tex]

[tex](3x - 1)(x + 4) \\ \\ = 3x(x + 4) - 1(x + 4) \\ \\ = 3 {x}^{2} + 12x - x - 4 \\ \\ = 3 {x}^{2} + 11x - 4[/tex]

[tex]\bold{ \green{ \star{ \orange{Mystique35}}}}⋆[/tex]

How far does a train travel in 12 hours at 115 miles per hour?

1,509 mi
1,265 mi
1,380 mi

Answers

Answer:1380

Step-by-step explanation: 12x115

Answer:

1,380

Step-by-step explanation: 12 times 115 gives you the product of 1,380. :)

Hope this is helpful

a rope of length 18 m is used to form a sector of a circle of radius 3.5 m on a school field. What is the size of the angle of the sector?​

Answers

Answer:

Perimeter of the sector = 2r + length of arc= 2(3.5)+11= 7+11=18 meters exactly the length of the rope.

Step-by-step explanation:

The perimeter of the sector is equivalent to the length of the rope which is 18 meters

Perimeter of the sector= 2 x radius + length of the arc

But length of arc= radius x central angle in radian

18= 2(3.5)+ 3.5(central angle in radians)

18=7+3.5 (central angle in radians)

18–7=3.5(central angle)

11=3.5(central angle)

central angle =11/3.5=3.14 radians or pi radians

Angle in degrees =pi radians x 360 degrees/2pi radians =pi radians x 180 degrees/pi radians = 180 degrees

Therefore the central angle = 180 degrees because pi radians is half of 2pi radians which is half of 360 degrees

Notes: This sector shape is a semicircle because the central angle is 180 degrees

Check: Length of Arc for semicircle =3.5(pi radians)=11 meters

Perimeter of the sector = 2r + length of arc= 2(3.5)+11= 7+11=18 meters exactly the length of the rope.

2. How many miles the trucks will have to drive for the costs of the trucks to be equal?

Answers

Step-by-step explanation:

kayo na po bahala mag calculate

Please help!
Geometry
10 points!

Answers

Answer: c= 6√2, d= 7√3

Explanation: Use the 45-45-90 theorem and solve for C, Use the 30-60-90 theorem and solve for D.

45 45 90
s s s√2
6 6 6√2
c=6√2

30-60-90
a a√3 2a
7√3 7 14
d=7√3

Find the perimeter of the figure.

Answers

Answer:

below

Step-by-step explanation:

p = 2( a + b)

p = 2(24 +16)

p =80 in

p semicircle

=πr

= 3.142 *8

= 25.136

p of figure

p =80 +25.136

p=105.136 in

In the accompanying diagram, ABC is isosceles, BC is extended to D. AB = AC. and M

Answers

Answer:

m∠ACD = 130

Step-by-step explanation:

If ABC is an isosceles, AB = AC and m∠A = 80°, then m∠B and m∠C is equal to 50°.

This is because angles in a triangle adds up to 180°.

180° - 80° = 100°/2 = 50°

∴ m∠ACD = 130°, this is because the interior opposite angles in a triangle is supplementary to the opposite exterior angle:

50° + 80° = 130°

Or

Angles on a straight line adds up to 180°.

180° - 50° = 130°

Help, please
no links

Answers

9514 1404 393

Answer:

  4/10 and 10/25

Step-by-step explanation:

If each of the ratios reduces to the same lowest terms, then they are a proportion. All are in lowest terms except the first pair. Reducing those gives ...

  4/10 = 10/25 = 2/5

4/10 and 10/25 form a proportion

__

All of the other pairs are pairs of different ratios, so do not form a proportion.

Help!!!!!!!!!!! Photo attached

Answers

Answer:

option A : 25

Step-by-step explanation:

Given :

P = (- 6, 7) , Q = ( 2 , 1 ) , R = ( -1 , -3)

Find the length of PQ ,QR , PR.

Using distance formula to find the lengths.

[tex]distance = \sqrt{(x_2 - x_1 )^2 + (y_ 2- y_1)^2[/tex]

[tex]PQ = \sqrt{(2 -- 6)^2 + (1-7)^2} = \sqrt{8^2 + 6^2 } = \sqrt{64 + 36 } =\sqrt{100} = 10\\\\QR = \sqrt{(2 --1)^2 + (-3-1)^2}= \sqrt{3^2 + 4^2} =\sqrt{9+ 16} =\sqrt{25} = 5\\\\PR = \sqrt{(-1--6)^2 + (-3 -7)^2} = \sqrt{5^2 + 10^2} = \sqrt{25 + 100} = \sqrt{125}[/tex]

Clearly , the triangle satisfies Pythagoras theorem :

Square of larger side = Sum of squares of other sides.

Therefore , PQR is a right triangle,

with base = 5, height 10 and slant height(hypotenuse) = [tex]\sqrt{125}[/tex] .

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

       [tex]=\frac{1}{2} \times 5\times 10\\\\= 5 \times 5 \\\\= 25 \ square\ units[/tex]

Which number line represents the solution set for the inequality -4(x + 3) S-2 – 2x?
-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7
-7 -6 -5 -4 -3 -2 -1 0 1 2 3
4 5 6 7
+
-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7
-7 -6 -5 -4 -3 -2:-1 0 1
2.
+
6
+
7
3 4
01
5
02

Answers

Answer:

the answer is the alphabet A at the picture

The circle must be on -5 and arrow drawn to the right. Hence the correct answer is number line A

Inequality expression

Given the inequality expression

-4(x+3) <= -2-2x

Expand the inequality

-4x - 12 <= -2-2x

Collect the like terms

-4x + 2x <= -2+12

-2x <= 10

Divide both sides by -2

-2x/-2 >= 10/-2

x >= -5

For the number line, the circle must be on -5 and arrow drawn to the right. Hence the correct answer is number line A.

Learn more on inequality expression: https://brainly.com/question/24372553

Find the equation of a sphere if one of its diameters has endpoints: (-14. -3, -6) and (-4, 7, 4) Note that you must move everything to the left hand side of the equation and that we desire the coefficients of the quadratic terms to be 1.

Answers

Answer:

[tex]x^2+y^2+z^2-18x-4y+2z-21=0[/tex]

Step-by-step explanation:

From the question we are told that:

Diameters has endpoints: [tex](-14. -3, -6) & (-4, 7, 4)[/tex]

Generally the equation for Center of The sphere is mathematically given by

 [tex]C=(\frac{-14+(-4)}{2},\frac{-3+(7)}{2},\frac{-6+(4)}{2})[/tex]

 [tex]C=(9,2,-1)[/tex]

Generally the equation for Radius of the sphere is mathematically given by

 [tex]R=\sqrt{(9-2)^2+(2-9)^2+(-1-2)^2}[/tex]

 [tex]R=\sqrt{107}[/tex]

Therefore the Equation of the Sphere is

 [tex](x-9)^2+(y-2)^2+(z+1)^2=107[/tex]

 [tex](x^2-18x+81)+(y^2-4y+4+(z^2+2z+1))=107[/tex]

 [tex]x^2+y^2+z^2-18x-4y+2z-21=0[/tex]

City A had a population of 10000 in the year 1990. City A’s population grows at a constant rate of 3% per year. City B has a population that is growing exponentially. In the year 2000, there were half as many people in B as in A. In the year 2010, the population of A was 20% more than the population of B.
When will the populations be equal? Give your answer in years after 1990.

Answers

Answer:

City A and city B will have equal population 25years after 1990

Step-by-step explanation:

Given

Let

[tex]t \to[/tex] years after 1990

[tex]A_t \to[/tex] population function of city A

[tex]B_t \to[/tex] population function of city B

City A

[tex]A_0 = 10000[/tex] ---- initial population (1990)

[tex]r_A =3\%[/tex] --- rate

City B

[tex]B_{10} = \frac{1}{2} * A_{10}[/tex] ----- t = 10 in 2000

[tex]A_{20} = B_{20} * (1 + 20\%)[/tex] ---- t = 20 in 2010

Required

When they will have the same population

Both functions follow exponential function.

So, we have:

[tex]A_t = A_0 * (1 + r_A)^t[/tex]

[tex]B_t = B_0 * (1 + r_B)^t[/tex]

Calculate the population of city A in 2000 (t = 10)

[tex]A_t = A_0 * (1 + r_A)^t[/tex]

[tex]A_{10} = 10000 * (1 + 3\%)^{10}[/tex]

[tex]A_{10} = 10000 * (1 + 0.03)^{10}[/tex]

[tex]A_{10} = 10000 * (1.03)^{10}[/tex]

[tex]A_{10} = 13439.16[/tex]

Calculate the population of city A in 2010 (t = 20)

[tex]A_t = A_0 * (1 + r_A)^t[/tex]

[tex]A_{20} = 10000 * (1 + 3\%)^{20}[/tex]

[tex]A_{20} = 10000 * (1 + 0.03)^{20}[/tex]

[tex]A_{20} = 10000 * (1.03)^{20}[/tex]

[tex]A_{20} = 18061.11[/tex]

From the question, we have:

[tex]B_{10} = \frac{1}{2} * A_{10}[/tex]  and  [tex]A_{20} = B_{20} * (1 + 20\%)[/tex]

[tex]B_{10} = \frac{1}{2} * A_{10}[/tex]

[tex]B_{10} = \frac{1}{2} * 13439.16[/tex]

[tex]B_{10} = 6719.58[/tex]

[tex]A_{20} = B_{20} * (1 + 20\%)[/tex]

[tex]18061.11 = B_{20} * (1 + 20\%)[/tex]

[tex]18061.11 = B_{20} * (1 + 0.20)[/tex]

[tex]18061.11 = B_{20} * (1.20)[/tex]

Solve for B20

[tex]B_{20} = \frac{18061.11}{1.20}[/tex]

[tex]B_{20} = 15050.93[/tex]

[tex]B_{10} = 6719.58[/tex] and [tex]B_{20} = 15050.93[/tex] can be used to determine the function of city B

[tex]B_t = B_0 * (1 + r_B)^t[/tex]

For: [tex]B_{10} = 6719.58[/tex]

We have:

[tex]B_{10} = B_0 * (1 + r_B)^{10}[/tex]

[tex]B_0 * (1 + r_B)^{10} = 6719.58[/tex]

For: [tex]B_{20} = 15050.93[/tex]

We have:

[tex]B_{20} = B_0 * (1 + r_B)^{20}[/tex]

[tex]B_0 * (1 + r_B)^{20} = 15050.93[/tex]

Divide [tex]B_0 * (1 + r_B)^{20} = 15050.93[/tex] by [tex]B_0 * (1 + r_B)^{10} = 6719.58[/tex]

[tex]\frac{B_0 * (1 + r_B)^{20}}{B_0 * (1 + r_B)^{10}} = \frac{15050.93}{6719.58}[/tex]

[tex]\frac{(1 + r_B)^{20}}{(1 + r_B)^{10}} = 2.2399[/tex]

Apply law of indices

[tex](1 + r_B)^{20-10} = 2.2399[/tex]

[tex](1 + r_B)^{10} = 2.2399[/tex] --- (1)

Take 10th root of both sides

[tex]1 + r_B = \sqrt[10]{2.2399}[/tex]

[tex]1 + r_B = 1.08[/tex]

Subtract 1 from both sides

[tex]r_B = 0.08[/tex]

To calculate [tex]B_0[/tex], we have:

[tex]B_0 * (1 + r_B)^{10} = 6719.58[/tex]

Recall that: [tex](1 + r_B)^{10} = 2.2399[/tex]

So:

[tex]B_0 * 2.2399 = 6719.58[/tex]

[tex]B_0 = \frac{6719.58}{2.2399}[/tex]

[tex]B_0 = 3000[/tex]

Hence:

[tex]B_t = B_0 * (1 + r_B)^t[/tex]

[tex]B_t = 3000 * (1 + 0.08)^t[/tex]

[tex]B_t = 3000 * (1.08)^t[/tex]

The question requires that we solve for t when:

[tex]A_t = B_t[/tex]

Where:

[tex]A_t = A_0 * (1 + r_A)^t[/tex]

[tex]A_t = 10000 * (1 + 3\%)^t[/tex]

[tex]A_t = 10000 * (1 + 0.03)^t[/tex]

[tex]A_t = 10000 * (1.03)^t[/tex]

and

[tex]B_t = 3000 * (1.08)^t[/tex]

[tex]A_t = B_t[/tex] becomes

[tex]10000 * (1.03)^t = 3000 * (1.08)^t[/tex]

Divide both sides by 10000

[tex](1.03)^t = 0.3 * (1.08)^t[/tex]

Divide both sides by [tex](1.08)^t[/tex]

[tex](\frac{1.03}{1.08})^t = 0.3[/tex]

[tex](0.9537)^t = 0.3[/tex]

Take natural logarithm of both sides

[tex]\ln(0.9537)^t = \ln(0.3)[/tex]

Rewrite as:

[tex]t\cdot\ln(0.9537) = \ln(0.3)[/tex]

Solve for t

[tex]t = \frac{\ln(0.3)}{ln(0.9537)}[/tex]

[tex]t = 25.397[/tex]

Approximate

[tex]t = 25[/tex]

Find the lateral surface area of the cylinder. Round your answer to the nearest tenth.

Answers

Answer:

The answer is "The second choice".

Step-by-step explanation:

[tex]r=6\\\\h=13 \\\\[/tex]

Formula:

[tex]A=2\pi rh[/tex]

[tex]=2\times 3.14 \times 6 \times 13\\\\=2\times 3.14 \times 78\\\\=3.14 \times 156\\\\=3.14 \times 156\\\\=489.84 \approx 489.8 ft^2[/tex]

Find the complement of the set given that
U = {x | x is in I and −3 ≤ x ≤ 7}.
(Enter your answers as a comma-separated list.)
{−1, 1, 3, 5, 7}

Answers

I think the answer is { -1, 1, 3, 5, 7}

Get brainiest if right!!!

10points if right!!

Answers

Answer:

the next three terms, 0.075,0.0375,0.01875 (common ratio 0.5)

the formula is 0.3*0.5^n-1

the formula for finding the nth term of a geometric sequence preset would be

a*r^n-1

a is first term

r is common ratio

Step-by-step explanation:

What is the surface area and volume of the sphere shown below?
Your response should show all necessary calculations and diagrams.

Answers

Answer:

ur mom

Step-by-step explanation:

doin doin

If you leave Louisville Ky at 8:15 am and arrive in Chicago at 2:25 pm how long did you travel ?

Answers

Answer: 6 hours and 10 minutes

Step-by-step explanation:

Let ​f(x)=x2+10x+37​ .

What is the vertex form off(x)?

What is the minimum value off(x)?



Enter your answers in the boxes.

Vertex form: f(x)=

Minimum value of f(x):

Answers

Answer:

f(x) = (x+5)^2 +12

The minimum value is 12

Step-by-step explanation:

f(x)=x^2+10x+37

The vertex will be the minimum value since this is an upwards opening parabola

Completing the square by taking the coefficient of x and squaring it adding it and subtracting it

f(x) = x^2+10x  + (10/2) ^2 - (10/2) ^2+37

f(x) = ( x^2 +10x +25) -25+37

    = ( x+5) ^2+12

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

The vertex is (-5,12)

The minimum is the y value or 12

What is the answer to this?

Answers

It’s d just trust I did it

PLEASE HELP!! Please answer all if you can and show answer clearly thankyou sm if u do

Answers

Answer:

Below:

Step-by-step explanation:

A) 0.15 (0.35 + 0.40 + 0.10 + 0.15 = 1)

B) 0.45

C) 0.40

A) the total probability has to equal 1.

To find the probability of rat subtract the other animals from1:

Rat = 1 - 0.35-0.4-0.1 = 0.15

Rat = 0.15

B) probability of cat or hamster equals the sum of their probabilities:

Cat = 0.35 + hamster = 0.1 = 0.45

Answer = 0.45

C) the probability of them both picking the same = dog x dog = 0.4 x 0.4 = 0.16

Answer = 0.16

What is the production matrix?

Answers

Answer:

[tex]\left[\begin{array}{ccc}3\\3.8\end{array}\right][/tex]

Step-by-step explanation:

Here we want to compute the product of two matrices, one 2x2, and other 2x1.

[tex]\left[\begin{array}{ccc}0.3&0.3\\0.35&0.4\end{array}\right]*\left[\begin{array}{ccc}4\\6\end{array}\right][/tex]

Remember that in the product, we multiply the rows of the first one by the columns of the second one, then the product is just:

[tex]\left[\begin{array}{ccc}0.3&0.3\\0.35&0.4\end{array}\right]*\left[\begin{array}{ccc}4\\6\end{array}\right] = \left[\begin{array}{ccc}0.3*4 + 0.3*6\\0.35*4 + 0.4*6\end{array}\right] = \left[\begin{array}{ccc}3\\3.8\end{array}\right][/tex]

Three lines intersect at point P, as shown in the diagram below. Find the measure of

Answers

Answer:

VPQ = 83°

Step-by-step explanation:

You can draw a circle around the point P, and a circle have 360°, so it means that the sum off all the angles have ro be 360°. Some of these angles have the same measure, because they're formed by the same lines segments, they are:

SPR = UPV; TPU = RPQ; TPS = VPQ

360 - SPR - UPV - RPQ - TPU = VPQ + TPS

As some of they are equal, we can just multiply they by 2:

360 - 2×SPR - 2×RPQ = 2× VPQ

360 - 2×35 - 2×62 = 2×VPQ

360 - 70 - 124 = 2×VPQ

2 VPQ = 166

VPQ = 166/2

VPQ = 83°

Other Questions
ENGLISH NERD CLICK HERE Which psychological domain would include a study of memory and intelligence? What term number will have 400 square in it? Checkable and debitable accounts in commercial banks and other financial institutions are classified as money because A. they sometimes earn an interest income for the depositor. B. banks hold currency in their vaults equal to the value of demand deposits. C. they are not liabilities of the banks. D. they are generally acceptable in the payment of debt. What is work and give an example? (science newton's law) 1. what do you dislike about your study?2. What do you hope to do after your graduation?3. Tell me about your best friend at school What is the area of the triangle What New Mexican community was hit hard by malnutrition? a. Albuquerque c. Gallup b. Taos d. all large cities suffered A field currently holds 20 tulips. The number of tulips will grow by 70% each year. The field can only sustain 300 plants. Use th logistic growth model to predict the population in the next 3 years, Match the the words with their definitions.1. merger one who invests money in a company or corporation2. tycoon the total amount of money or property owned or used by a corporation or business3. capital items of property an individual or business owns4. assets one having great wealth and power5. corporation the merger of several businesses into one6. stockholder a combining of entities If a randomly thrown dart hits the board below, what is the probability it will hit the shaded region? A spinner has an equal chance of landing on each of its six numbered regions. After spinning it, what are the chances it lands in region 2 or 4? PLEASE HELP!! Look at photo Does Portia represents "womanly virtue "or is she a manipulative virago or bad tempered woman? Justify with reference to the text PLEASE HELP FAST I NEED HELP WITH THIS! Annie wants to find a character about singing. Which radical should she find first? (mandarin) in your own words, what is the definition for Exocytosis? Which of the following is not a property of zero? A motor has an internal resistance of 12.1 . The motor is in a circuit with a current of 4.0 AmpsWhat is the voltage? Which of the forces of molecular attraction is the weakest? A London dispersion forces B hydrogen bond C single covalent bond D dipole dipole interactions