Find a • b. a = 5i + 7j, b = -4i + 3j (5 points)
<1, 10>
<-20, 21>
1
41

Answers

Answer 1

Answer:

[tex]a\cdot b[/tex] = 1

Step-by-step explanation:

Given that,

Vector [tex]a=5i+7j[/tex]

Vector [tex]b=-4i+3j[/tex]

We need to find [tex]a{\cdot} b[/tex] means the dot product of a and b. So,

[tex]a{\cdot} b=(5i+7j){\cdot} (-4i+3j)[/tex]

We know that,

[tex]i{\cdot}i, j{\cdot}j,k{\cdot}k=1\ \text{and}\ i{\cdot}j= j\cdot i=0[/tex]

So,

[tex]a{\cdot} b=(5i+7j){\cdot} (-4i+3j)\\\\=5i{\cdot}(-4i)+5i{\cdot} 3j+7j\cdot(-4i)+7j\cdot 3j\\\\=-20+21\\\\=1[/tex]

So, the value of [tex]a\cdot b[/tex] is 1.

Answer 2

Answer:

1

Step-by-step explanation:


Related Questions

Find the missing side length. Leave your answers radical in simplest form. PLEASE HURRY

Answers

Answer:

the answers for x and y are both 12

What is the square root of -1

Answers

Answer:

the awnser is sqrt(-1) = i

Solve for x. 2x+3≤x−5 x≤−8 x≤2 x≤8 x≤−2

Answers

Answer:

x≤−8

Step-by-step explanation:

2x+3≤x−5

Subtract x from each side

2x-x+3≤x-x−5

x+3≤−5

Subtract 3 from each side

x+3-3≤−5-3

x≤−8

Answer:

[tex]\huge \boxed{x \leq -8}[/tex]

Step-by-step explanation:

[tex]2x+3 \leq x-5[/tex]

[tex]\sf Subtract \ x \ from \ both \ parts.[/tex]

[tex]2x+3 -x\leq x-5-x[/tex]

[tex]\sf Simplify \ the \ inequality.[/tex]

[tex]x+3 \leq -5[/tex]

[tex]\sf Subtract \ 3 \ from \ both \ parts.[/tex]

[tex]x+3-3 \leq -5-3[/tex]

[tex]\sf Simplify \ the \ inequality.[/tex]

[tex]x \leq -8[/tex]

Use absolute value to express the distance between -12 and -15 on the number line


A: |-12-(-15)|= -37
B: |-12-(-15)|= -3
C: |-12-(-15)|= 3
D: |-12-(-15)|= 27​

Answers

C
I-12-(-15)l
l-12+15l
l3l = 3

please help me answer these questions :(

Answers

Answer:

a) ∠X = 67.4°

ii) ∠Y = 22.6°

b) Hypotenuse = 13 miles

ii) Length of each congruent = 4.33 miles

c) Distance of mall from point A = 5.21 miles

d) Distance os mall from point B = 8.17 miles

e) Difference = 2.96 miles

ii) Amount it will cost = $1,628,000

Step-by-step explanation:

Because of the length of the solution, I sent it as an attachment to this answer.

What is the equivalent of 27/5 in decimal form?

Answers

5.4 is equivalent to 27/5.

Answer: 5.4

Step-by-step explanation: 27/5, so 5x5 makes 25 and 2 remaining so 5x0.4=2 so answer is 5+0.4 which equals to 5.4

even though the elimination method is easy I still have trouble with it

Answers

Answer:

(1,2)

Step-by-step explanation:

x+4y = 9

2x -4y= -6

Add the equations together

x+4y = 9

2x -4y= -6

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

3x +0y = 3

3x=3

Divide by 3

3x/3 = 3/3

x=1

Now find y

x+4y = 9

1 +4y =9

Subtract 1 from each side

4y = 8

Divide by 4

4y/4 = 8/4

y =2

What is (2/3 x 3/5) - (3/4 x 1/6)

Answers

Answer:

2/3×3/5=2/3. 3/4×1/6=1/8

2/3-1/8=11/40

Answer:

[tex] \boxed{ \frac{11}{40} }[/tex]

Step-by-step explanation:

[tex]( \frac{2}{3} \times \frac{3}{5} ) - ( \frac{3}{4} \times \frac{1}{6} )[/tex]

Reduce the numbers with Greatest common factor 3

⇒[tex] \mathsf{(2 \times \frac{1}{5} ) - ( \frac{1}{4} \times \frac{1}{2} )}[/tex]

Calculate the product

⇒[tex] \mathsf{( \frac{2}{5} )- ( \frac{1}{4} \times \frac{1}{2}) }[/tex]

Subtract the fractions

⇒[tex] \mathsf{ \frac{2 \times 8 - 1 \times 5}{40} }[/tex]

⇒[tex] \mathsf{ \frac{16 - 5}{40} }[/tex]

⇒[tex] \mathsf{ \frac{11}{40} }[/tex]

Hope I helped!

Best regards!

A group of fitness club members lose a combined total of 28 kilograms in 1 week. There are approximately 2.2 pounds in 1 kilogram. Assuming the weight loss happened at a constant rate, about how many pounds did the group lose each day?

Answers

Answer:

8.8 pounds

Step-by-step explanation:

Given the following :

Combined weight loss which occurred within a week = 28 kg

Number of days in a week = 7 days

1 kilogram (kg) = 2.2 pounds

Combined weight loss in pounds that occurs within a week:

Weight loss in kg × 2.2

28kg * 2.2 = 61.6 pounds

Assume weight loss occurred at a constant rate :

Weight lost by the group per day :

(Total weight loss / number of days in a week)

(61.6 pounds / 7)

= 8.8 pounds daily

Answer:

88

Step-by-step explanation:

Found the answer and I am doing the quiz rn lel

Cancel the common factor of the numerator and the denominator and write specified expression

Answers

Step-by-step explanation:

Hello,

I hope you mean to cancel the common factor that exists in numerator and denominator,right.

so, Let's look for the common factor,

here, the expression is,

=4(x-2)/ (x+5)(x-2)

so, here we find the common factor is (x-2)

now, we have to cancel it. And after cancelling we get,

=4/(x+5)

Note:{ we cancel the common factor if the common factors are in multiply form.}

Hope it helps

Let ​f(x)=−5x+18 and ​g(x)=x2+15.

Find ​f(−2​)−​g(−2​).

Answers

Answer:

21

Step-by-step explanation:

-5(-2)-(-2)²+15

10-(4)+15

10-4+15

21

Answer:

9

Step-by-step explanation:

f(x)=−5x+18

f(-2) = -5(-2)+18 = 10+18 = 28

​g(x)=x^2+15

g(-2) = (-2)^2 +15 = 4+15 = 19

f(02) - g(-2) = 28 - 19 = 9

PLZZZZ helpppp will give good rating say thanks and say thank you on your account

Yak Travel Agency arranges trips for climbing Mount Everest. For each trip, they charge an initial fee in addition to $0.15 for each vertical meter climbed. For instance, the price for climbing all the way to the summit, which is 3500 meters above the base of the mountain, is $645. Let F represent the fee (in dollars) of a trip where they climbed ddd vertical meters. Complete the equation for the relationship between the fee and vertical distance.

Answers

X+3500•0.15=645
X=120

F= 0.15d + 120

g Refer to the Number of Motorcycles Narrative} Are these probabilities true or false? ?a. P(X > 1)=0.35 b. P(X ≤ 2)=0.85 c. P(1 ≤ X ≤ 2)=.6 d. P(0 < X < 1)=0 e. P(1 ≤ X < 3)=.6 True False

Answers

Answer:

False.

Step-by-step explanation:

Probability distribution is the function which describes the likelihood of possible values assuming a random variable. The variance distribution is the squared value of each the difference by the mean. values of probability are squared and then their sum is taken to calculate variance deviation. The number of motorcycles greater than 1 has probability of 0.35 so the probability of x = 1 must also be 0.35.

Which graph represents x < 15?

Answers

Answer:

B

Step-by-step explanation:

x<15

There is an open circle at 15 and the line goes to the left

A sample of 31 observations is selected from a normal population. The sample mean is 11, and the population standard deviation is 3. Conduct the following test of hypothesis using the 0.05 significance level. H0: μ ≤ 10 H1: μ > 10 Is this a one- or two-tailed test?

Answers

Answer:

The  test is a two -tailed test

Step-by-step explanation:

From the question we are told that

    The  sample size is n  =  31

     The  sample mean is  [tex]\= x =11[/tex]

      The sample standard deviation is  [tex]\sigma = 3[/tex]

       The null hypothesis is  [tex]H_o: \mu \le 10[/tex]

         The  alternative hypothesis is  [tex]H_1 : \mu > 10[/tex]  

         The level of significance is [tex]\alpha = 0.05[/tex]

 

The test  statistics is mathematically represented as

       [tex]t = \frac{ \= x - \mu }{ \frac{\sigma }{\sqrt{n} } }[/tex]

substituting values

      [tex]t = \frac{ 11 - 10 }{ \frac{3}{\sqrt{ 31} } }[/tex]

     [tex]t = 1.85[/tex]

The  p- value is mathematically represented as

       [tex]p-value = p( t > 1.856) = 0.0317[/tex]

Looking at the value of  [tex]p-value \ and \ \alpha[/tex] we see that [tex]p-value < \alpha[/tex] hence we reject the null hypothesis

Given the that the p value is less than 0.05 it mean the this is a two-tailed test

3 divided by 6 it hard

Answers

Answer:

3/6 = 1/2 = 0.5

Step-by-step explanation:

3 / 6 = 1/2 = 0.5

3/6 = 1/2 or 0.5 ......

The ratio of red beads to blue beads on a necklace is 4:7. If there are 16 red beads, how many blue ones are there?​

Answers

Answer:

There are 28 beads

Step-by-step explanation:

Total ratio:

[tex]{ \sf{ (4 + 7) = 11}}[/tex]

let total beads be x:

[tex]{ \sf{ \frac{4}{11} \times x = 16 }} \\ \\ { \sf{x = \frac{11 \times 16}{4} }} \\ x = 44 \: beads[/tex]

Blue beads:

[tex] = 44 - 16 \\ = 28 \: \: beads[/tex]

What is 7 x -5?........

Answers

Answer:

-35

Step-by-step explanation:

7*5*(-1)

The solution to the expression 7 * -5 is -35

How to evaluate the expression

From the question, we have the following parameters that can be used in our computation:

7 * -5

Evaluate all the products in the expression

so, we have the following representation

7 * -5 = -35/1

Evaluate all the quotients in the expression

so, we have the following representation

7 * -5 = -35

Lastly, we have

7 * -5 = -35

Hence, the solution is -35

Read more about expressions at

https://brainly.com/question/30492964

#SPJ6

m= -1/2 and the point (3, -6) which is the point -slope form of the equation

Answers

Answer:

y+6=-1/2(x-3)

Step-by-step explanation:

Point slope form: y-y1=m(x-x1)

Given that:

m=-1/2 and point (3, -6), you just add these numbers into the equation, and this gives:

y+6=-1/2(x-3)

Hope this helped!

Have a nice day!

Show that Reſiz) = -Im(z)​

Answers

Step-by-step explanation:

[tex]re(i(x + yi) = - im(x + yi) \\ re(xi - y) = - im(x + yi) \\ - y = - (y) \\ - y = - y \\ proved \: is \: correct[/tex]

Your’re in charge of evening entertainment for an important client group You use the company credit card to take their four representatives out to dinner. Two people order the steak entree for 32.50 Two people order the grilled tuna for 28.90 and you order the lasagna for 24.95 When the bill comes you tip 20% what is the amount of tip you leave

Answers

Answer:

total amount paid = 32.5 + 28.9 + 24.95 = 86.35

20% of the total amount paid = 0.2 * 86.35 = 17.27

you tip 17.25$

Evaluate integral _C x ds, where C is
a. the straight line segment x = t, y = t/2, from (0, 0) to (12, 6)
b. the parabolic curve x = t, y = 3t^2, from (0, 0) to (2, 12)

Answers

Answer:

a.    [tex]\mathbf{36 \sqrt{5}}[/tex]

b.   [tex]\mathbf{ \dfrac{1}{108} [ 145 \sqrt{145} - 1]}}[/tex]

Step-by-step explanation:

Evaluate integral _C x ds  where C is

a. the straight line segment x = t, y = t/2, from (0, 0) to (12, 6)

i . e

[tex]\int \limits _c \ x \ ds[/tex]

where;

x = t   , y = t/2

the derivative of x with respect to t is:

[tex]\dfrac{dx}{dt}= 1[/tex]

the derivative of y with respect to t is:

[tex]\dfrac{dy}{dt}= \dfrac{1}{2}[/tex]

and t varies from 0 to 12.

we all know that:

[tex]ds=\sqrt{ (\dfrac{dx}{dt})^2 + ( \dfrac{dy}{dt} )^2}} \ \ dt[/tex]

[tex]\int \limits _c \ x \ ds = \int \limits ^{12}_{t=0} \ t \ \sqrt{1+(\dfrac{1}{2})^2} \ dt[/tex]

[tex]= \int \limits ^{12}_{0} \ \dfrac{\sqrt{5}}{2}(\dfrac{t^2}{2}) \ dt[/tex]

[tex]= \dfrac{\sqrt{5}}{2} \ \ [\dfrac{t^2}{2}]^{12}_0[/tex]

[tex]= \dfrac{\sqrt{5}}{4}\times 144[/tex]

= [tex]\mathbf{36 \sqrt{5}}[/tex]

b. the parabolic curve x = t, y = 3t^2, from (0, 0) to (2, 12)

Given that:

x = t  ; y = 3t²

the derivative of  x with respect to t is:

[tex]\dfrac{dx}{dt}= 1[/tex]

the derivative of y with respect to t is:

[tex]\dfrac{dy}{dt} = 6t[/tex]

[tex]ds = \sqrt{1+36 \ t^2} \ dt[/tex]

Hence; the  integral _C x ds is:

[tex]\int \limits _c \ x \ ds = \int \limits _0 \ t \ \sqrt{1+36 \ t^2} \ dt[/tex]

Let consider u to be equal to  1 + 36t²

1 + 36t² = u

Then, the differential of t with respect to u is :

76 tdt = du

[tex]tdt = \dfrac{du}{76}[/tex]

The upper limit of the integral is = 1 + 36× 2² = 1 + 36×4= 145

Thus;

[tex]\int \limits _c \ x \ ds = \int \limits _0 \ t \ \sqrt{1+36 \ t^2} \ dt[/tex]

[tex]\mathtt{= \int \limits ^{145}_{0} \sqrt{u} \ \dfrac{1}{72} \ du}[/tex]

[tex]= \dfrac{1}{72} \times \dfrac{2}{3} \begin {pmatrix} u^{3/2} \end {pmatrix} ^{145}_{1}[/tex]

[tex]\mathtt{= \dfrac{2}{216} [ 145 \sqrt{145} - 1]}[/tex]

[tex]\mathbf{= \dfrac{1}{108} [ 145 \sqrt{145} - 1]}}[/tex]

The hypotenuse of a right triangle is 5 inches long. One of the legs is 1 inch longer than the other. What is the length (in inches) of the longer leg?

Answers

Answer:  4  inches

Step-by-step explanation:

1. We gonna find the the length of the right triangle legs using Phitagor theorem.

c²=a²+b²  (1)   , where c is triangle's  hypotenuse

a and b are the triangle's  legs.

Let the leg a =x,    so leg b=x+1 inches

Now we can write the equation using (1)

25=x²+(x+1)²

25=x²+x²+2*x+1

2*x²+2*x-24=0     ( divide by 2 both sides of the equation)

x²+x-12=0

Find the discriminant D=1+12*4=49

√D=7

x1= (-1+7)/2=3     x2=(-1-7)/2=-4 - x2=-4 not possible so length of the leg can not be negative.

So the shorter leg a=x= 3 inches

The longer leg b=x+1=4 inches

Bighorn sheep are beautiful wild animals found throughout the western United States. Data for this problem are based on information taken from The Desert Bighorn, edited by Monson and Sumner 9University of Arizona Press). Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information:
x 1 2 3 4 5
y 14 18.9 14.4 19.6 20.0
∑x=15 ; ∑y=87.3;∑x2=55; ∑y2=1569.77; ∑xy=275
(a) Draw a scatter diagram.
(b) Find the equation of the least-squares line, and plot the line on the scatter diagram of part (a).
(c) Find the correlation coefficient r. Find the coefficient of determination . What percentage of variation in y is explained by the variation in x and the least squares model?

Answers

Answer:

The answer and explanation are below

Step-by-step explanation:

i followed the data that was given in the question.

∑x=15 ; ∑y=87.3;∑x2=55; ∑y2=1569.77; ∑xy=275

a.)  please refer to the attachment for the scatter diagram. Y was plotted against X.

b. The equation is given as:

Y = b₁ + b₀X

∑x=15 ; ∑y=87.3;∑x2=55; ∑y2=1569.77; ∑xy=275

b₁ = n∑xy - (∑x)(∑y)/n(∑x²) - (∑x)²

b₁ = 5 x 275 - 15 x 87.3/5 x 55 - (15²)

= 1375-1309.5/275-225

= 65.5/50

= 1.31

b₀ = 87.3/5 - 1.31(15/5)

= 87.3/5 - 1.31x3

= 13.53

the regression line is

Y = 13.53 + 1.31X

please refer to the attachment for the diagram for the regression line.

c. we are required to find r.

r = n∑XY - (∑X)(∑Y)/√n∑X²-(∑X)² × √n∑y²-(∑y)²

∑x=15 ; ∑y=87.3;∑x2=55; ∑y2=1569.77; ∑xy=275

inserting these values:

r = 5 x 275-(15)(87.3)/√275-225 x √7848.85 - 7621.29

= 65.5/106.69

= 0.6139

Coefficient of determination = r²

r = 0.6139

r² = 0.3769 = 37.69%

Therefore 37.69% variation in y is explained by variation in x and the least square model.

6. Ideal measure of Central tendency and dispersion are:
a. Mean and mean deviation
b. Median and quartile deviation
c. Median and standard deviation
d. Mean and standard deviation​

Answers

Answer:

median and quartile deviation

Decimal divison need answer no pdf

Answers

Answer:

1.84

Step-by-step explanation:

If you like my answer than please mark me brainliest thanks

The sum of two positive integers is 67. When the smaller integer is subtracted from twice the larger, the result is 38. Find the two integers.

Answers

Answer:

Step-by-step explanation:

x+y = 67

2x-y = 38

Add the equations together

3x = 108

x = 36

y = 67-x = 31

Benjamin’s and David’s ages add up to 36 years. The sum of twice their respective ages also add up to 72 years. Find their ages

Answers

Answer:Benjamin’s age = 30 and David’s age = 6

Explanation:

Let x be the age of Benjamin
Let y be the age of David

x + y = 36

And 2x + 2y = 72

If we plug 30 for x and 6 for y we get:

30 + 6 = 36
36 = 36

2(30) + 2(6) = 72
60 + 12 = 72
72 = 72

=

Answer:

It can be any two numbers that sum up to 36.

eg:18+18,30+6,15+21

Step-by-step explanation:

Given:

Let Benjamin's age be x and David's age y.

x+y=36

2x+2y=72

Solution:

As twice of 36=72, any two numbers that add up to 36 ,will give a sum of 72 after multiplying them with 2.Therefore ,Benjamin's and David's age can be any set of numbers that sum up to 36.

I don’t really get this question

Answers

You can put [tex]n[/tex] different elements in order in [tex]n![/tex] different ways.

So, you can visit 12 different cities in [tex]12!=479001600[/tex] different ways.

Answer: 479,001,600

Step-by-step explanation:

There are 12 ways to go to the first place, 11 for the second, ten for the third, and so on. So 12! Means 12x11x10x9x8x7x6x5x4x3x2x1.

Find the equation of the line: with an intercept of 4 and a y intercept of -1.5

Answers

Answer:

y = 4x -1.5

Step-by-step explanation:

The slope intercept form of a line is given by

y = mx+b  where m is the slope and b is the y intercept

y = 4x -1.5

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