Solve. Between [0, 2pi]
2cos^2x+7cosx+3=0
Answers
9514 1404 393
Answer:
x = {2π/3, 4π/3}
Step-by-step explanation:
The equation can be factored as ...
(cos(x) +3)(2cos(x) +1) = 0
The solutions are the values of x where the factors are zero.
cos(x) +3 = 0
cos(x) = -3 . . . . . . no real solution
__
2cos(x) +1 = 0
cos(x) = -1/2
x = arccos(-1/2) = 2π/3
The other solution in the desired interval is ...
x = 2π -(2π/3) = 4π/3
The solutions are x∈ {2π/3, 4π/3}.
![Solve. Between [0, 2pi]2cos^2x+7cosx+3=0](https://brainimage.s3.us-east-005.backblazeb2.com/answers/attachments/mdxPgxnTfEbPWTdmFDnLMpgudyNpdDV9.png)
Related Questions
How is a ratio table used to graph equivalent ratios?
Answers
Answer:
Ratio tables show equivalent ratios between two quantities. They can help you find equivalent ratios in order to solve problems.
hope this helps:) emoji slammm
simplify 2 1/2 times 3/4
Answers
Answer:
[tex] \frac{5}{2} \times \frac{3}{4} \\ \frac{15}{8} [/tex]
Answer:
15/8
Step-by-step explanation:
2.5/2 = 1.25
1.25/2 = 0.625
2.5 - 0.625 = 1.875
1.875 = 75/40 = 15/8
A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 40 % salt and Solution B is 90 % salt. She wants to obtain 50 ounces of a mixture that is 80 % salt. How many ounces of each solution should she use?
Answers
Answer:
The scientist must use 10 ounces of Solution A and 40 ounces of Solution B.
Step-by-step explanation:
Since a scientist has two solutions, which she has labeled Solution A and Solution B, each containing salt, and she knows that Solution A is 40% salt and Solution B is 90% salt, and she wants to obtain 50 ounces of a mixture that is 80% salt, to determine how many ounces of each solution should she use the following calculation must be performed:
100 x 0.9 + 0 x 0.4 = 90
90 x 0.9 + 10 x 0.4 = 85
80 x 0.9 + 20 x 0.4 = 80
50 x 0.8 = 40
Therefore, the scientist must use 10 ounces of Solution A and 40 ounces of Solution B.
Please Help i need this done
Answers
Answer:
i think u add 2.5 everytime
Step-by-step explanation:
for example start with(0, 2.5) 0n the graph then add 2.5 to 2.5 then keep adding if im wrong srry
Leslie tunes a guitar with 6 strings and a piano with 37 times as many strings.
How many strings did the piano have?
Choose 1 answer:
(Choice A)
The piano has 422 strings, because 37×6=422.
(Choice B)
The piano has 222 strings, because 37×6=222.
(Choice C)
The piano has 6 strings, because 37÷6=6 remainder 1.
Answers
Multiply 6*7 = 42
Multiply 3*6 =18 + 4 = 22
37
*6
222
A 50 foot ladder is set against the side of a house so that it reaches up 40 feet. If Aisha grabs the ladder at its base and pulls it 9 feet farther from the house, how far up the side of the house will the ladder reach now? (The answer is not 31 ft.) Round to the nearest tenth of a foot.
Answers
Answer: ~31.3
first use the pythagorean theorem. a^2+(40)^2=50^2.
simply. a+1600=2500. subtract 1600 from both sides. a^2=900.
square root both sides to get a= 30
then find how far the top of the ladder is from the ground once in its new position.
a^2+(39)^2=50^2.
simplify. a^2+1512=2500. subtract 1512 from both sides to get a^2=979.
square root both sides to get a=31.288975. round to the nearest tenth to get a=31.3
Answer:
Step-by-step explanation: iT'S 31.3
8 (6-4x) = 12
equation with parentheses
Answers
Answer:
x=9/8
Step-by-step explanation:
Solve the inequality. 4/5v < 7/15
Answers
Answer:
v < 7/12
Step-by-step explanation:
Find the slope of the line passing through the points (-4,-5) and (3, -5).
Answers
A woman decides to have children until she has her first girl or until she has five children; whichever happens first. Find the expected value and standard deviation of X. Let X represent the number of children she has. Assume that she is equally likely to give birth to a boy or a girl on each child, and that gender is independent between children.
(a) Write out and sketch the complete probability distribution function for X.
(b) Write out and sketch the complete cumulative distribution function for X.
(c) Find the expected value and standard deviation of X.
Answers
Answer:
E(X) = 1.9375
SD(X) = 1.20
Step-by-step explanation:
Let :
G = girl ; B = Boy
P(G) = 0.5 ; P(B) = 0.5
Sample space :
G, BG, BBG, BBBG, BBBBG, BBBBB
Using the multiplication rule of independence :
P(G) = 0.5
P(BG) = 0.5 * 0.5 = 0.25
P(BBG) = 0.5 * 0.5 * 0.5 = 0.125
P(BBBG) = 0.5 * 0.5 * 0.5 * 0.5 = 0.0625
P(BBBBG) = 0.5 * 0.5 * 0.5 * 0.5 * 0.5 = 0.03125
P(BBBBB) = 0.5 * 0.5 * 0.5 * 0.5 * 0.5 = 0.03125
Creating a probability distribution table :
X = 1, 2, 3, 4, 5
For X = 5 ;
P(BBBBG) + P(BBBBB) = 0.03125 + 0.03125 = 0.0625
X :___ 1 ____ 2 ____ 3 _____ 4 _____ 5
P(X) : 0.5 __ 0.25 _ 0.125 _0.0625 _0.0625
The expected value E(X) :
√(ΣX * P(X)) = (1*0.5)+(2*0.25)+(3*0.125)+(4*0.0625)+(5*0.0625) = 1.9375
The standard deviation SD(x) :
√(ΣX²*p(x) - E(X)²
√((1^2*0.5)+(2^2*0.25)+(3^2*0.125)+(4^2*0.0625)+(5^2*0.0625) - 1.9375^2)
√(5.1875 - 3.75390625)
√1.43359375
SD(X) = 1.197
SD(X) = 1.20
55 times 4 and time 3 equals what?
Answers
Answer:
55 times 4 =220
220 times 3 =660
One hundred volunteers who have agoraphobia (fear of open and crowded space) are available for a study. Fifty are selected at random and are given the drug imipramine, which is believed to be effective in treating agoraphobia. The other 50 are given a placebo. A psychiatrist evaluates the symptoms of all volunteers after two months to determine if there has been substantial improvement in the severity of their symptoms.
What type of study is this?
A. Matched pair design
B. Observational study
C. Completely randomized block design
D. Completely randomized design
Answers
Answer:
D. Completely randomized design
Step-by-step explanation:
Based on the description given about the experiment above and the manner in which the subjects were assigned to each of the treatment groups available, we can deduce that the study was conducted using a completely randomized design. The subjects weren't matched or blocked for any variable such as sex, height, age or any other variable. They were just evenly split randomly into the two available treatment levels ( those who receive the treatment and the placebo) group. With this design, all subjects have an equal chance of being in any of the two groups and the selection bias is almost totally eliminated using this sort of design as errors are being considered as arising from experimental faults.
Find the vertex and focus of
(x+3)^2 = 4 (y+2)
Answers
Answer: I don’t know how to solve x but look at the picture
Step-by-step explanation: Hope this help :D
Solve for x:
3-a/x-a=1/a
PLEASE HELP NEED ASAPPP WILL GIVE BRAINLIEST TO FIRST CORRECT ANSWERRRR
Answers
hope this helps!!
a2 (exponent 2)
x= - _______
1 - 3a + a2 (exponent 2)
Mark brainliest please.
Will mark brainliest for area.
Answers
Answer:
c
Step-by-step explanation:
first, find the area of the rectangle thing,
A = lw
14 x 8
112
but, there is a semicircle in it so you need to subtract that from it:
A = πr^2/2
A = π(4)^2/2
A = π16/2
A = 8π
A ≈ 25.132741228718346
then subtract that area from the area of the rectangle:
112 - 25.132741228718346
86.867258771281654
or about 89.9
THE TOPIC IS: AREA OF CIRCLES!! PLEASE HELP ME WITH THIS QUESTION!!! WHATS THE ANSWER?? I WILL GIVE YOU BRAINLIEST AND A THANKS!!! AND PLS PUT AN EXPLANATION!! THANK YOU GUYS SO MUCHHHH!!
Answers
Answer:
If you are finding area then the area is 254.34
Step-by-step explanation:
Area of a circle- 3.14 times radius squared
3.14 (pi) times 81 (9 squared)
What is $45.79 multiplied by .50 equal
Answers
Answer:
686.85
Step-by-step explanation:
Answer:
$45.79 multiplied by .50 equals 22.895
Which is the better definition of line of best fit?
Answers
A line of best fit guides a line through a scatter plot of data points that best describes the association between those points.
What is line of best fit?
A line of best fit guides a line through a scatter plot of data points that best describes the association between those points. Statisticians typically utilize the least squares approach to arrive at the geometric equation for the line, either through manual computations or regression analysis software.
A line of best fit can be approximately specified utilizing an eyeball the method by marking a straight line on a scatter plot so that the numeral of points above the line and below the line stands about equal (and the line passes via as many points as possible).
To learn more about line of best fit refer to;
https://brainly.com/question/1518824
#SPJ2
1. If x and y are vertical angles, then y _____ has the same measure as x.
2. If x and y are adjacent angles, then x and y are ____ acute
Fill in blank with (sometimes, never, always)
Someone please help me for brainliest and 30 points. Please DO NOT answer if u don’t know. And do not put in the comment here’s a link cause it leads to no where. Ty.
Answers
Answer: 1. Sometimes 2. Always
Step-by-step explanation:
I am pretty sure these are right.
A computer game was originally priced at $59.99. It was marked down 15%. Then it was moved to a clearance rack marked "Take an additional 50% off the lowest marked price." What was the final price of the computer game?
Answers
Answer:
25.50 is the final price
Step-by-step explanation:
First find the new price at 15% off
59.99 * 15%
59.99 * .15
9.00
Subtract 9 dollars from the price
59.99-9.00
50.99
Now take 50% off
50.99 * 50%
50.99*.50
25.50
50.99-25.50
25.50
A bicycle has a listed price of $529.95 before tax. If the sales tax rate is 7.5%. Find the total cost of the bicycle with sales tax included. Round your answer to the nearest cent, as necessary.
Answers
Answer:
569.95 dallars
Step-by-step explanation:
If there are 7 days in a week, how many days are there in 6 weeks?
Answers
Answer:
42
Step-by-step explanation:
Answer: 42
Step-by-step explanation: 7 x 6 = 42
What is the place value of the digit 5 in the number 1,029.756
Answers
Answer:2
Step-by-step explanation:
Answer: Its the tens place, do you not pay attention in school?
Plzzzz answer fast......
Answers
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Answers
Step-by-step explanation:
11.True
12.False
13.False
14.False
15.True
16.False
17.False
18.True
19.True
20.False
Answer:
here
Step-by-step explanation:
Solve the system of equations
Answers
Monica hizo galletas de dos tamaños como se muestra en la imagen. ¿Cuánto mide el lado Z de la galleta más grande?
Answers
-4x+3x<4 what is the awenswer to this equation
Answers
Answer:
X > -4
Step-by-step explanation:
Collect the like terms which literally leaves you with -x<4
Then just changes the signs, hence the answer.
Please mark brainliest!
Adrian is putting streamers across the ceiling of his dining room to decorate for his nephews birthday party. The ceiling is rectangular. Its area is 122,5 square feet, and its
width is 7 feet. How long should Adrian cut a streamer that will run the length of the ceiling?
Answers
Answer: 17.5 feet long.
Gina is shopping for a new bicycle. The price of the bicycle is $300 and there is an 8% sales tax. Gina wants to know the total price of the bicycle including soles tax. How much sales tax does Gina pay on the bicycle? Enter the amount in the table.
Answers
Answer:
24
Step-by-step explanation:
The person above me is incorrect . I got it right on the i-Ready Quiz!