solve the equation 2 cos x + 1 = 0 , 0 <= x <= 2pi PLEASE HELP! WILL AWARD!

Answers

Answer 1
Im not saying its right but I got 0,2π3,4π3,and2π  f(x)=2cos2x−cosx−1=0
Solve this quadratic equation for cos x.
Since a + b + c = 0, use shortcut.
One real root is cos x = 1 and the other is cosx=ca=−12.
Trig table and unit circle -->
a. cos x = 1 --> arc x = 0, and arc x=2π
b. cosx=−12 --> arc x=±2π3
The arc −2π3 is co-terminal to the arc: 4π3
Answers for (0,2π):
0,2π3,4π3,and2π
Answer 2

The solution of the given trigonometric expression is x = 2π/3.

Use the concept of trigonometric ratio defined as:

Trigonometric ratios depend on the value of the ratio of sides of a triangle which is right-angled and contains the values of all trigonometric functions.

The ratios of a right-angled triangle's sides with regard to a certain acute angle are known as it's trigonometric ratios.

The given expression is:

2 cos x + 1 = 0

Where,

0 ≤ x ≤ 2π

To solve it,

Subtract  both sides,

2 cos x  = - 1

Divide by 2 on both sides,

cos x = -1/2

Take cos inverse on both sides,

[tex]x = cos^{-1} (\frac{1}{2})[/tex]

Since  cos(2π/3) = -1

x = 2π/3

Now since 2π/3 lies between  0 ≤ x ≤ 2π

Hence,

The solution of the given expression is x = 2π/3

To learn more about trigonometric ratios visit:

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Related Questions

Which expression is equivalent to .02m(n-5)-.02(m+10)

Answers

Removing parentheses.
Subtract 0.02m from -0.1m to get -0.12m

Answer is~ 
.02mn-0.12m-0.2

Answer:

thank you

Step-by-step explanation:

Help! WHAT IS THE VALUE OF X, and can you show how you got it please?

Answers

see the picture attached with letters to better understand the problem

in the right triangle ABD
applying the Pythagoras theorem
8²=AD²+(x+4)²-----> AD²=64-(x+4)²------> equation 1

in the right triangle ADC
applying the Pythagoras theorem
12²=AD²+(2x+1)²-----> AD²=144-(2x+1)²------> equation 2

equate equation 1 and equation 2
64-(x+4)²=144-(2x+1)²-------> 64-[x²+8x+16]=144-[4x²+4x+1]
64-x²-8x-16=144-4x²-4x-1
4x²-x²-8x+4x=144-1-64+16
3x²-4x=95
3x²-4x-95=0

using a graph tool----> to resolve the second order equation
see the attached figure N 2
the solution is
x=6.33

the answer is
x=6.33 units

What are three consecutive odd integers that have a sum of 39?

Answers

Consecutive odd integers ascend by 2 units so the integers can be represented with x, x + 2, and x + 4. The word sum implies an addition.

x + x + 2 + x + 4 = 39
3x + 6 = 39
3x = 33
x = 11

The three consecutive odd integers are 11, 13, and 15

A certain arithmetic sequence has the recursive formula an = an-1 + d. If the common difference between the terms of the sequence is -13, what term follows the term that has the value 13?

Answers

In an Arithmetic sequence, each term is obtained by adding the common difference in the previous term as shown in the recursive formula.

The common difference of the sequence is -13. This means, if we -13 to a term we'll obtain the next term.

If a term is 13, the term that will be next to 13 can be obtained by adding -13 to it.

So, 

13 + ( -13) = 13 - 13 = 0

Thus, the next term will be 0.

The fourth term of a sequence is 14. Each term of the sequence is 8 less than the previous term. Which recursive formula represents the situation?

Answers

[tex]a_4=14\\d=-8\\\\a_n=a_1+(n-1)d\\\\a_n=14+(n-1)\cdot(-8)\\\\a_n=14-8n+8\\\\a_n=22-8n[/tex]

Please pretty please help me fast

Answers

Region 1: 
Ordered pair -- (0, 50)
Explanation: The red region represents solutions to the red line inequality that are not solutions to the blue line. 

Region 2:
Ordered pair -- (50, 0)
Explanation: The purple region represents solutions to both the red line and blue line. 

Region 3: 
Ordered pair -- (20, - 10)
Explanation: The blue region represents solutions to the blue line inequality that are not solutions to the red line.

Region 4: 
Ordered pair -- (0, 0)
Explanation: The white region represents all points/ordered pairs that are not solutions to either inequality. 

Two cubes have surface areas of 72 square feet and 98 square feet. what is the ratio of the volume of the small cube to the volume of the large cube?

Answers

Let's denote the sides of the small and bigger cubes a and b respectively. Then, we can write that 6[tex] a^{2} [/tex]=72, a=[tex] 2\sqrt{3} [/tex] and 6[tex] b^{2}=98, b=[tex] \frac{7}{sqrt{3}} [/tex]. The volume of the smaller cube is [tex] 2 sqrt{3} ^{3} [/tex] =  [tex] 24 sqrt{3} [/tex]. The volume of the bigger cube is [tex] \frac{7}{sqrt{3}}^{3} [/tex] = [tex] \frac{343}{3sqrt{3}}{[/tex]. We have to find  [tex] \frac{24 sqrt{3}}{frac{343}{3sqrt{3}} [/tex] = 216/343 

Answer:

Ratio of the volumes of the cubes = 216 : 343

Step-by-step explanation:

Since surface area of a cube is represented as 6a² where a is the side of a cube.

Let a is one side of large cube and b is the side of smaller one.

Ratio of their surface area = [tex]\frac{6a^{2} }{6b^{2}}=\frac{72}{98}[/tex]

[tex](\frac{a}{b})^{2}=\frac{36}{49}[/tex]

[tex]\frac{a}{b}=\sqrt{\frac{36}{49}}[/tex]

[tex]\frac{a}{b}=\frac{6}{7}[/tex]

Now ratio of the volumes = [tex]\frac{a^{3} }{b^{3}}=(\frac{1}{b})^{3}[/tex]

Ratio = [tex](\frac{6}{7})^{3}=\frac{216}{343}[/tex]

Therefore, ratio of the volumes of the cubes = 216 : 343

the weight of 1in ^3 of water is 0.036 pounds. A container contains
528.768 pounds of water. what is the volume of water in the container

Answers

density of water  = 0.036 pounds/in^3

density = weight/volume

0.036 = 528,768 /  volume

required volume =  528,768 / 0.036 =  14,688,000  in^3

The volume of the water in the container is calculated by dividing the total weight of water (528.768 pounds) by the weight of one cubic inch of water (0.036 pounds), resulting in 14688 cubic inches.

To find the volume of water in the container, we first consider the weight of 1 cubic inch of water, which is given as 0.036 pounds. We know that the container holds 528.768 pounds of water. To find the volume, we divide the total weight of water in the container by the weight of one cubic inch of water.
Volume = Total Weight / Weight per Unit Volume

Volume = 528.768 pounds / 0.036 pounds/in³

Volume = 14688 cubic inches

If you need the volume in other units, such as gallons, you must convert cubic inches to gallons using the appropriate conversion factor.

Simplify the equation 7.5+N+9.63

Answers

To simplify the equation, you just have to add like terms. This means adding 9.63 and 7.5. Once you've found your sum, which is 17.13, your equation will be N+17.13.

Add  7.5+9.63 which would be 17.13

17.13+N

Sally goes out to lunch and has the option of a soup or a salad and then a turkey, ham, or club sandwich. Which tree diagram correctly shows all of her choices?

Answers

the answer should be B 



The answer is B.
Hope this helps!

Someone please help me?

Answers

see the attached picture:

Y=|x| vertically stretched by a factor of 5

Answers

jdbsjxbejdbdjsndjwjdnjwkebd


Which of the following proportions can be used to prove AE || DK in the proof below? Select all that apply.
the pictures in order are
a
b
c
d
and the last picture is a figure if an awnser is missing please tell me if that one is the correct one




Answers

Answer: DA:FA=KE:EF, DF:DA=KF:KE and FA:DA=EF:KE are correct.

Explanation: Since, [tex]\triangle EFA[/tex] and [tex]\triangle KFD[/tex] are similar triangles.

Because, [tex]\angle FAE= \angle FDK[/tex] and [tex]\angle FEA= \angle FKD[/tex] (because EA and KD are parallels. And, [tex]\angle F[/tex] is common angle for these triangles.

Therefore, according to the property of similar triangles.

FE:EK= FA:AD, FE:FK=FA:FD and DF:DA=KF:KE .

Thus, first, second and third options are correct.

A card is being drawn from a standard deck of playing cards. Find each probability.
1.P(Jack or ten)
2.P(red or black)
3.P(queen or club)
4.P(red or ace)
5.P(diamond or black)
6.P(face card or spade)

Answers

These are 6 questions and 6 answers.

To find each probability we will use the definition of probability:

Probability = number of positive outcomes / number of total possible outcomes

1) P(Jack or ten)


Answer: 2/13 ≈ 0.12


Justification:

i) Positive outcomes: A standard deck of cards has 4 jacks and 4 tens, then those are 4 + 4 = 8 different positive outcomes.

ii) Possible outcomes: a standard deck of cards has 52 different cards, so, that is a total of 52 different possible outcomes

 
iii) Probability, P


P = number of positive outcomes / number of total possible outcomes

P = 8 / 52 = 2/13 ≈ 0.15

2.P(red or black)


Answer: 1

Justification:

i) Positive outcomes

Half of the cards are red and half of the cards are black, so they both add for the total of the cards = 52


ii) Possible outcomes: 52 cards


iii) Probaility, P 

P = number of positive outcomes / number of total possible outcomes

P = 52 / 52 = 1

3.P(queen or club)


Answer: 4/13 ≈ 0.31

Justification:


i) Positive outcomes

There are 4 Queens.

There are 1/4 of 52 clubs = 1/4 × 52 = 13 clubs.

But you cannot add all of them, because one club is the Quenn of Clubs.

Then, the total number of different Queens and clubs is 4 + 13 - 1 = 16



ii) Possible outcomes: 52 different cards


iii) Probaility, P

P = number of positive outcomes / number of total possible outcomes

P = 16 /52 = 4 / 13 ≈ 0.31


4.P(red or ace)


Answer: 7 / 13 ≈ 0.54


Justification:


i) Positive outcomes

Half of the cards are red: 26

There are 4 aces. 

Since 2 aces are red, the number of different red and aces cards is: 26 + 4 - 2 = 28

ii) Possible outcomes: 52 different outcomes


iii) Probaility, P

P = number of positive outcomes / number of total possible outcomes

P = 28 / 52 = 7 / 13 ≈ 0.54

5.P(diamond or black)


Answer: 1/2 = 0.5

Justification:

i) Positive outcomes

There are 52 / 4 = 13 diamonds

There are 26 black cards.


All the diamonds are black cards.

Then, the number of different diamond or black cards is 13 + 26 - 13 = 26

ii) Possible outcomes: 52 different cards.

iii) Probaility, P

P = number of positive outcomes / number of total possible outcomes

P = 26 / 52 = 1/2 = 0.5

6.P(face card or spade)

Answer: 11/26 ≈ 0.42


Justification:

i) Positive outcomes

Face cards are jacks, queens and kings. That is 3 × 4 = 12 different cards.

The spades are 13 cards.

Since, 3 of the faces are spade cards, the number of different cards of those types are 12 + 13 - 3 = 22


ii) Possible outcomes: 52 different cards


iii) Probaility, P

P = number of positive outcomes / number of total possible outcomes

P = 22 / 52 = 11 / 26 ≈ 0.42

if the number of bacteria in a colony double every 330 minutes and there is currently a population of 1100 bacteria what will the population be 990 minutes from now

Answers

This can be done in a straightforward manner.

If it doubles every 330 minutes, it will increase by a factor of 4 after 990 minutes.

1,100 * 4 = 4,400


please help type the integer that represents the correct answer the absolute value of 7

Answers

The answer is:  " 7 " .
________________________________________________________

Assume that the line passes through the point (−2,4) and is parallel to the line through the points ( −4,4) and (−5,−1).find the equation of this line in slope intercept form.

Answers

let m be the slope and b the y-intercept.

m=(y₂-y₁)/(x₂-x₁)

m= (-1-4)/(-5-(-4))

m= 6

y=mx+b

4=6(-4)+b

b=28

y=6x+28

(-2,4)

parallel means the slopes are the same:

4=6(-2)+b

4=-12+b

b=16

y=6x+16






Company A charges a $120 annual fee plus $7 per hour car share fee. Company B charges $100 plus $9 per hour. What is the minimum number of hours that a car share needs to be used per year to make company A a better deal?

Answers

Answer:

11

Step-by-step explanation:

The Tran Family drove 1,246 miles during a vacation that lasted 14 days. How many miles on average did they drive each day? :3

Answers

To find the average miles they drove each day, divide the total amount of miles by the number of days they drove.

1246 / 14 = 89

The Tran Family drove an average of 89 miles every day.
Hey there!

To solve this problem, divide the numbers 1,246 and 14  . . .

1,246 ÷ 14 = 89 ←

Once you divide the miles and days, you will find your answer (89).

The correct answer is 89.

They drove 89 miles each day on average.

I hope this helps you.
Have a great day! :)

Which of the following describes the probability distribution below?
A.) The mean is greater than the median, and the majority of the data points are to the left of the mean.
B.) The mean is greater than the median, and the majority of the data points are to the right of the mean.
C.) The median is greater than the mean, and the majority of the data points are to the left of the mean.
D.) The median is greater than the mean, and the majority of the data points are to the right of the mean.

Answers

Answer: A.) The mean is greater than the median, and the majority of the data points are to the left of the mean.

It is clear that most of the data (around 75%) is consist of value 1, which is the leftmost part of the data. Since it was more than 50% of the data, the median should be 1.

if 75% data is 1, it need 25% data with value at least 5 to make the means equal to 2. The means would be bigger than 1 but less than 2, so most(75% data is 1) of the data would be on the left of the mean

If we draw a normal distribution bell curve as shown in the attachment, we can see that the bell curve is skewed to the right . This means it has a right tail. This means few points are to the right of the mean. In other words, we can say that majority of the data points are to the left of the mean

Since the majority of the data points are to the left, the median will also be to the left of the mean which indicates median is lesser than mean . In other words, mean is greater than median

So, answer is: A.) The mean is greater than the median, and the majority of the data points are to the left of the mean.

Which table represents a direct variation function?

x y x y x y
-3 -4.5 -5.5 -3 -3 -7.5
-1 -3.0 -5.5 -1 -1 -2.5
2 -1.5 -5.5 2 2 5.0
5 0.0 -5.5 5 5 12.5
10 1.5 -5.5 10 10 25.0

x y
-5.5 10
-4.5 8
-3.5 6
-2.5 4
-1.5 2

Answers

The answer to this question is B Ed

The table that represents a direct variation function is

x y

-3 -7.5

-1 -2.5

2 5.0

5 12.5

10 25.0

How to determine the table?

For a table to represents a direct variation, the following must be true

k = y/x

Where k represents the constant of variation

In table 3,  we have:

k = 25.0/10 = 12.5/5 = 5.0/2 = -2.5/-1 = -7.5/-3

This gives

k = 2.5

The value of k is the same for all input and output values

Hence, the table that represents a direct variation function is the table 3

Read more about direct variation at:

https://brainly.com/question/6499629

Will give brainliest-H(t)=-16t^2+28t
T is time in seconds.
How long will it take for the dolphin to make one jump, show your work.

Answers

For this case we have the following equation:
 H (t) = - 16t ^ 2 + 28t
 When the dolphin finishes a jump, then the height is equal to zero.
 We have then:
 -16t ^ 2 + 28t = 0
 We look for the roots of the polynomial:
 t1 = 0
 t2 = 1.75 s
 Therefore, the dolphin takes 1.75 seconds to make a jump.
 Answer:
 
it will take for the dolphin to make one jump about:
 
t = 1.75 s

Simplify: (3 + 4i) + (2 - 3i) - (5 - 6i)

Answers

(3 + 2 - 5) and (4i - 3i + 6i)
= 0 + 7i
The answer is:  " 7 i " .
________________________________________________________
Explanation:
________________________________________________________
(3 + 4i) + (2 - 3i) - (5 - 6i) =

(3 + 4i) + 1(2 - 3i) - 1(5 - 6i) ;   ←  Note that the coefficient, "1" is implied; 
                    since any value, multiplied by "1" , results in that same value.
_____________________________________________________________
Note the "distributive property" of multiplication:
_____________________________________________________________
a(b + c) = ab + ac ;

a(b – c) = ab – ac .
_____________________________________________________________
We have:

(3 + 4i) + 1(2 - 3i) - 1(5 - 6i) ;

Start with:

 " + 1(2 - 3i) "  =  (1*2) - (1*3i)  = 2 - 3i ; 

Then, we examine:

 " - 1(5 - 6i) "  =  (-1*5) + (-1 * -6i) = -5 + (+6i) =  -5 + 6i ; 
______________________________________________________________
And we rewrite the entire expression:
______________________________________________________________
   3 + 4i + 2 - 3i - 5 + 6i  ; 

Combine the "like terms" ; as follows:

   3 + 2 - 5 = 5  - 5 = 0 ; 

   4i - 3i + 6i = 1 i  + 6i = 7 i

     0 + 7i = 7i .
_______________________________________________________
The answer is:  " 7 i " .
_______________________________________________________ 

Three consecutive numbers that have a sum of 159. What are the numbers?

Answers

Let n = the first number. n + 1 = the second and n + 2 = the third number. So....

n + (n + 1) + (n + 2) = 159
3n + 3 = 159
3n = 156
n = 52

n + 1 = 53
n + 2 = 54

So the numbers are 52, 53, and 54. 
The middle one is their average, 159/3 = 53.

The numbers are 52, 53, 54.

The angle of depression from point R to point S is angle .

Answers

the angle of depression means it's going down starting at R and going down to Point S so it really depends on the question at hand


Final answer:

The question involves high school level mathematics, specifically geometry and trigonometry, discussing the angle of depression, cross-sectional area, angles, distances, and congruent triangles.

Explanation:

The question relates to the angle of depression and concepts of geometry involving angles and distances. In the context provided, the angle of depression from point R to S is being discussed, but not enough information is given to define the angle. The references to cross-sectional area, small-angle approximation, and congruent triangles touch on topics in geometry and trigonometry that are critical to understanding the properties of shapes, sizes, and angles in mathematical problems.

In the mathematical equations provided, 'S' is used as a variable representing a stress value, with reference to pressure units of N/m², and 'r' represents a radius which is then used to calculate an area. The references to a graph with a slope and 'y = mx + b' appear to relate to linear equations and representations in coordinate geometry.

The descriptions involving angle vector, position vector, arc length vector, and angle of distance between two points separated by an angle further contribute to the idea that this question falls under the Mathematics category, addressing high school level concepts in geometry and trigonometry.

With a quick explanation please

Answers

[tex]\dfrac{40}{5x-2}=\dfrac{55}{6x+6}\ \ \ |\text{cross multiply}\\\\40(6x+6)=55(5x-2)\\\\240x+240=275x-110\ \ \ |-240\\\\240x=275x-350\ \ \ \ |-275x\\\\-35x=-350\ \ \ \ \ |:(-35)\\\\\boxed{x=10}[/tex]

Look at the picture.

If cosine x is approximately.9511 what is the measurement of x to the nearest degree? Approximately what is the sine of the angle that is complementary to x

Answers

Sin(x) = .2588     Given

ARCSin (x) = x = ARCSin(.2588)        Using the calculator   = 14.9988 degrees  ( ~ 15 degrees)   

COMPLIMENTARY angle is the angle which added to 'x' will equal 90      so the COMPLIMENTARY Angle is 75 degrees

Using the calculator again    cos (75) = .2588   The same as the complimentary angle's SIN !!!

A girl scout sells 3 boxes of cookies during week 1. She has a goal to sell twice as many cookies each week as she did the week before. If she succeeds in doing this during weeks 2, 3, 4, and 5, how many boxes will she sell all together? a0

Answers

Week Two: 6 Boxes
Week Three: 12 Boxes
Week Four: 24 Boxes
Week Five: 48 Boxes

Final Answer: 96 Boxes
(Add them all together)
If she wants to double the number of cookies she sells, then you just multiply by 2.

Week 1: 3 cookies
Week 2: 6 cookies
Week 3: 12 cookies
Week 4: 24 cookies
Week 5: 48 cookies

3+6+12+24+48 = 93. 

All together, she sold 93 cookies. 

Hope this helped! :)



x(t) = t^3 - 12t^2 + 36t
Velocity = x'(t) = 3y^3 - 24t + 36 = 0
x'(t) = t^2 - 8t + 12 = 0
x'(t) = t^2 - 6t - 2t + 12 = 0
x'(t) = t(t - 6) - 2(t - 6) = 0
x'(t) = (t - 2)(t - 6) = 0
t = 2 and t = 6 must be the roots.

Is my answer of D "2 and 6" correct based on this work?

Answers

Yes you have the right idea. You find the derivative to get the velocity function and then determine when the velocity is zero. That turns out to be at t = 2 and t = 6. Both are correct. The final answer is correct.

The only flaw I see is that you wrote 
x'(t) = 3y^3 - 24t + 36
on line 2 when it should be
x'(t) = 3t^2 - 24t + 36

Other than that it looks perfect.

The perimeter of a parallelogram is 30 ft and its length is 5 ft. What is the length of the other side?

Answers

given p = 30

l = 5



therefore p= 2 (a +b)

30 = 2 (5)+2b

2b=30-2 (5)=20

2b = 20

b=20/2=10

° ° the otherside is equal to 10 ft
°
A parallelogram has two equal sides.

Let the length be L 

The width is  W

P = L + L + W + W

P = 2L + 2W

P = 2*(L + W)

P = 30,  L = 5

P = 2*(L + W)

30 = 2*(5 + W)

30/2 =  (5 + W)

15 = 5 + W

5 + W = 15

W = 15 - 5

W = 10

The length of the other side is 10 feet.
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