sin^6x + cos^6x = 1/4

Answers

Answer 1

Answer:

[tex]\displaystyle x = \frac{\pi}{4} + k\, \pi[/tex] for integer [tex]k[/tex] (including negative numbers.)

Step-by-step explanation:

Pythagorean Identity: [tex]\sin^{2}(x) + \cos^{2}(x) = 1[/tex]. Equivalently, [tex]\cos^{2}(x) = 1 - \sin^{2}(x)[/tex].

Rewrite the original equation and apply this substitution to eliminate [tex]\cos(x)[/tex]:

[tex]\displaystyle \sin^{6}(x) + \cos^{6}(x) = \frac{1}{4}[/tex].

[tex]\displaystyle (\sin^{2}(x))^{3} + (\cos^{2}(x))^{3} = \frac{1}{4}[/tex].

[tex]\displaystyle (\sin^{2}(x))^{3} + (1 - \sin^{2}(x))^{3} = \frac{1}{4}[/tex].

Let [tex]y = \sin(x)[/tex] ([tex]-1 \le y \le 1[/tex].) The original equation is equivalent to the following equation about [tex]y[/tex]:

[tex]\displaystyle y^{6} + (1 - y^{2})^{3} = \frac{1}{4}[/tex].

Expand the cubic binomial in the equation:

[tex]\displaystyle y^{6} + 1 - 3\, y^{2} + 3\, (y^{2})^{2} - (y^{2})^{3} = \frac{1}{4}[/tex].

[tex]\displaystyle y^{6} + 1 - 3\, y^{2} + 3\, y^{4} - y^{6} = \frac{1}{4}[/tex].

Simplify to obtain:

[tex]\displaystyle 1 - 3\, y^{2} + 3\, y^{4} = \frac{1}{4}[/tex].

Rearrange and simplify:

[tex]12\, y^{4} - 12\, y^{2} + 3 = 0[/tex].

[tex]3\, (2\, y^{2} - 1)^{2} = 0[/tex].

[tex]2\, y^{2} - 1 = 0[/tex].

[tex]\displaystyle y^{2} - \frac{1}{2} = 0[/tex].

Solve for [tex]y[/tex]:

Either [tex]\displaystyle y = \frac{1}{\sqrt{2}}[/tex] or [tex]\displaystyle y = -\frac{1}{\sqrt{2}}[/tex].

If [tex]\displaystyle \sin(x) = y = \frac{1}{\sqrt{2}}[/tex], then [tex]\displaystyle x = \frac{\pi}{4} + 2\, k\,\pi[/tex] for all [tex]k\in \mathbb{Z}[/tex].

On the other hand, if [tex]\displaystyle \sin(x) = y = \frac{1}{\sqrt{2}}[/tex], then [tex]\displaystyle x = \frac{3\, \pi}{4} + 2\, k\,\pi = \frac{\pi}{4} + (2\, k + 1) \, \pi[/tex] for all [tex]k\in \mathbb{Z}[/tex].

Combine both situations to obtain:

[tex]\displaystyle x = \frac{\pi}{4} + 2\, k\, \pi[/tex] for all [tex]k \in \mathbb{Z}[/tex].


Related Questions

Multiply: (2x+y) (n2-3xy+y2)

Answers

Answer:

[tex]{ \tt{(2x + y)( {n}^{2} - 3xy + {y}^{2} )}} \\ = { \tt{(2x {n}^{2} - 3 {x}^{2}y + 2x {y}^{2} + {n}^{2}y - 3x {y}^{2} + {y}^{3} )}} \\ = { \tt{ {y}^{3} - xy(y + 3x) + {n}^{2} y }}[/tex]

Hello!

(2x+y) (n2-3xy+y2)

2x* n²= 2xn²

2x* -3xy = -6x²y

2x* y² = 2xy²

y*n² = yn²

y*-3xy = -3xy²

y* y² = y³

=>

2xn²- 6x²y + 2xy² +yn²- 3xy² +y³

HELPPP MEE PLEASE!!!
Consider the function shown on the graph.

Answers

Answer:

Domain x ≥ - 5

Range y ≥ - 2

Step-by-step explanation:

x ≥ - 5

y ≥ - 2

Can anyone help pls :)? Thank you

Answers

Answer: 6

Explanation: The EXACT calculation would be 5.9215.. so the closest approximation would be
6, as it's only about .08 -ish away from 6.

Answer:

It's D:5.3

Step-by-step explanation:

√28 =5.29

Round off therefore is 5.3

Please help!

This is a part 2 of a question, I found the first one and couldn’t find the second one. These are from edginuity. If you guys need the first part lmk.

Answers

Answer:

The vertical line test is basically a way to determine whether or not a graph is a function.  All three of the options are accurate, so I would select all three.

Let me know if you have any other questions!

Select the correct answer.

Which equation matches the function shown in the graph?

Answers

Answer:

D. y = cos(4x)

Step-by-step explanation:

The graph passes through the points y = 0 and x = 3π/8

So you solve x = 3π/8 into 4 answers, which is equal to 0 is the correct answer.

A fair spinner has 10 equal sections: 3 red, 3 blue and 4 green.
It is spun twice.
What is the probability of getting 2 different colours?

Answers

Answer:

11/30

Step-by-step explanation:

Help help help help help

Answers

0 and 4 are the answers

Answer: 0 and 4

Step-by-step explanation:

nick was scuba diving at -32 1/2 feet if he descends another 8 3/5 feet what is his location ?

Answers

Answer:

-41 1/10

Step-by-step explanation:

subtract the two numbers may i get brainliest plz

This is a really simple fraction problem. All we have to do is realize that, because he is descending, the [tex]8\frac{3}{5}[/tex] is actually negative, so we get [tex]-32\frac{1}{2}-8\frac{3}{5}=-41\frac{1}{10}[/tex] which can also equal -41.1

Find the shortest side of a triangle whose perimeter is 64 if the ratio of two of its sides is 4:3 and the third side is 20 less than the sum if the other two

Answers

Answer:

The shortest side of the triangle is 18

Step-by-step explanation:

Let the sides the triangle be x, y and z.

From the question, the perimeter of the rectangle is 64, that is

x + y + z = 64 ...... (1)

Also, the ratio of two of its sides is 4:3, that is x:y = 4:3, then we can write that x/y = 4/3 ⇒ 3x = 4y ...... (2)

The third side, z, is 20 less than the sum of the other two, that is

z + 20 = x + y ...... (3)

Substitute equation (3) into (1)

Then,

z + 20 + z = 64

2z +20 = 64

2z = 64 - 20

2z = 44

z = 44/2 k

z = 22

From equation (3)

z + 20 = x + y

Then, k

22 + 20 = x +y

42 = x + y

x = 42 - y ...... (4)

Substitute this into equation 2

3x = 4y

3(42-y) = 4y

126 - 3y = 4y

4y + 3y = 126

7y = 126

y = 126/7

y = 18

Substitute this into equation (4)

x = 42 - y

x = 42 - 18

x = 24

∴ x = 24, y = 18 and z = 22

Hence, the shortest side of the triangle is 18.

The mean age of 5 women in an office is 35 years old.
The mean age of 5 men in an office is 24 years old.
What is the mean age (nearest year) of all the people in the office?

Answers

Answer:

29.5

Step-by-step explanation:

(5×35)+(5×24)/10

175+120/10

295/10

=29.5

Please help, the question is in the picture

Answers

Answer:

per = 18a         7a+2a+7a+2a

area = 14 [tex]a^{2}[/tex]      7a*2a

Step-by-step explanation:

Answer:

(i) 18a

(ii) 14[tex]a^2[/tex]

Step-by-step explanation:

i: 7a+7a+2a+2a

      14a+4a

         18a

ii: 7a*2a

     14a2

I hope this helps!

Write the expression 4^4(4^-7)(4) using a single
exponent.
4^-28
4^-4
4^-3
4^-2

Answers

Answer:

4^(-2)

Step-by-step explanation:

4^4(4^-7)(4)

We know that a^b * a^c = a^(b+c)

4^4(4^-7)(4^1)

4^(4+-7+1)

4^(-2)

Find the vertical asymptotes of the function (x-1)(x-3)^2(x+1)^2/(x-2)(x+2)(x-1)(x+3)​

Answers

Answer:

x=2, x=-2, x=-3

Step-by-step explanation:

-check if anything simplifies

(x-1)(x-3)²(x+1)² / (x-2)(x+2)(x-1)(x+3), simplify (x-1)

(x-3)²(x+1)² / (x-2)(x+2)(x+3)

-make the denominator 0 to find the asymptotes

(x-2)(x+2)(x+3) = 0

(x-2) =0 gives x = 2 asymptote

(x+2) =0 gives x= -2 asymptote

(x+3) = 0 gives x=- 3 asymptote

find the value of x.

Answers

Answer: x=35

Step-by-step explanation:

To find the value of x, we can use the Pythegorean Theorem because this is a right triangle.

Pythagorean Theorem: a²+b²=c²

[tex]12^2+x^2=(x+2)^2[/tex]             [exponent and distribute]

[tex]144+x^2=x^2+4x+4[/tex]       [subtract both sides by 144]

[tex]x^2=x^2+4x-140[/tex]             [subtract both sides by x²+4x]

[tex]-4x=-140[/tex]                       [divide both sides by -4]

[tex]x=35[/tex]

Now, we know that x=35.

Fifteen years from now, Atli’s age will be 4 times his current age. What is his current age?

Answers

Answer:

he is three i think

Step-by-step explanation:

someone please help me with this question​

Answers

Answer:

Step-by-step explanation:

The diagram is given to you below. I could not change <C so that it was theta. So C = theta.

So C is the reference angle. Call it theta when you think of it. The diagram shows you how cos(C) must be set up.

The adjacent side is 7

The hypotenuse is 18

theta = C = cos-1(7/18) = 67.11

To the nearest degree 67.11 = 67

If 55% people in a city like Cricket, 30% like Football and the remaining like nother games, then what per cent of the people like other games? If the total people is 60 lakh, find the exact number who like each type of games Answer it fast, no spam please



write in notebook ​

Answers

[tex]\large{\dag\:{\underline{\underline{\frak{\pmb{\red{Answer:-}}}}}}}[/tex]

Cricket = 55%Football = 30%Other games = Remaining (?)

So, the percent of people who like other games equals:

= 100 – (55 + 30)

= 100 – 85

= 15%

If the total no. of. people is 60,00,000:

★ Cricket

= 60,00,000 × 55/100

= 33,00,000

★ Football

= 60,00,000 × 30/100

= 18,00,000

★ Other sports

= 60,00,000 × 15/100

= 9,00,000

Triangle QRP is congruent to triangle YXZ. What is the perimeter of triangle YXZ?
What is the perimeter of triangle YXZ?

Answers

Answer:

Perimeter of XYZ = Perimeter of QRP

Step-by-step explanation:

Since congruent then

P of XYZ = P of QRP

. Doanh nghiệp dự tính đầu tư góp vốn liên doanh với số tiền ban đầu là 500 trđ, trong vòng 4 năm, lãi suất dự kiến là 12%/năm. Tính tổng số lãi của hoạt động đầu tư liên doanh thu được sau khi kết thúc liên doanh ?

Answers

i dont understand nun of that

what is the solution to Y=-2x²+4x+8
Y=-4x+16

Answers

Hi there!

[tex]\large\boxed{(2, 8)}[/tex]

Solve by setting the two equations equal to each other:

-2x² + 4x + 8 = -4x + 16

Move all terms to one side:

-2x² + 4x + 4x + 8 - 16 = 0

Simplify:

-2x² + 8x - 8 = 0

Factor out a negative 2 from each term:

-2(x² - 4x + 4) = 0

Factor:

-2(x - 2)² = 0

Set the factor equal to 0 to solve:

(x - 2)² = 0

x - 2 = 0

x = 2

Substitute this value of x into an equation to find the shared y value:

y = -4(2) + 16 = 8

A group has more than $120 to spend. The inequality 5x + 20 > 120 represents the cost to rent a hall for a conference, where x represents the number of hours the group can rent the hall. Which of the following is the solution for this situation?

Answers

Answer:

x>20

Step-by-step explanation:

You want to try and get the x alone so

5x + 20 > 120

     -20     -20  Subtract 20 from each side

5x        > 100

5x/5    > 100/5 Divide 5 from each side

       x  > 20

Х
49°
X =
degrees
What do I do

Answers

Answer:

x = 139

Step-by-step explanation:

The exterior angle is equal to the sum of the opposite interior angle

x = 49 +90

x = 139

An exterior angle of a triangle is equal to the sum of its interior opposite angles.

[tex] \bf \large \implies \: x \: = \: 49 \degree \: + \: 90 \degree[/tex]

[tex] \bf \large \implies \: x \: = \: 139 \degree [/tex]

Which answer shows 0.00897 written in scientific notation?
From what I heard it's not D​

Answers

Answer:

B

Step-by-step explanation:

The decimal number 0.00897 written in scientific notation is 8.97 ×10^3 and it has significant figures

Answer:

8.97 * 10⁻³

Step-by-step explanation:

0.00897 = [tex]\frac{8.97}{1000}=8.97 * 10^{-3}[/tex]

Place the decimal point after the first nonzero number.

Write the power of 10,

(i) If we move the decimal to the right, the power of 10 decrease by number of moves.

(ii) If we move the decimal to the left, the power of 10 increase by the number of moves

Click the photo to solve the photo

Answers

Answer:

A=2

B=4

C=6

D=5

E=7

F=8

G=3

H=1

Step-by-step explanation:

explanation is in the picture!

Given the function g(x) = x^2 + 5x + 14, determine the average rate of change
of the function over the interval 1 < x < 7.

Answers

Answer:

13

Step-by-step explanation:

The average rate of change is

f(7) - f(1)

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

7-1

f(7) = 7^2 + 5*7 +14 = 49 +35 +14=98

f(1) = 1^2 +5(1)+14 = 1+5+14=20

98-20

--------

7-1

78/6

13

f The difference of 8 and 3 is multiplied by one-quarter of the sum of 7 and 5 37 vedanta Excel in Mathematics​

Answers

Answer:

15

Step-by-step explanation:

first find f which is (8-3) × ( 1/4 × 7 + 5)

simplify

5 × (1/4 ×12)

5 × 3

15 is thw answer

b) Tìm ba cách viết số hữu tỉ -11/25 dưới dạng tổng của hai số hữu tỉ dương.

Answers

Bạn ơi tổng hai số hữu tỉ dương làm sao bằng âm được ạ? Bạn xem lại đề có sai không ạ ^^

Sally spent half of her allowance going to the movies. She washed the family
car and earned 6 dollars. What is her weekly allowance if she ended with
17 dollars ?

Answers

does it give the answer choice or is it a blank space?

help me please and thank youu

Answers

Answer:

-3

Step-by-step explanation:

y - y1 = m(x - x1) m = slope

y - 5 = -3(x - 17) slope = -3

Answer:

-3

Step-by-step explanation:

A kindergarten class had a total of 15 boys 9 girls , what is the ratio of girls to boys in that class ?

Answers

Answer:

9:15

girls : boys

Step-by-step explanation:

Answer:

9:15

Or 3:5 when reduced

Step-by-step explanation:

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No food of any kind __________ into the examination room.is to beis to be takento takenwas to taking help asap no wrong answers---------------------- If the outliers are not included what is the mean of the data set 76,79,80,82,50,78,79,81,82 solve for x4 + x 9 A cell membrane is very specific about what it allows to cross.how does this help the cell? What text evidence supports Machiavellis primary purpose to persuade readers that a conquering prince must destroy a former republic if he hopes to hold it? Select three options. the list of cities Rome and Sparta conquered the portrayal of Greece as being held by Sparta the explanation of how Rome held Capua, Carthage, and Numantia the description of liberty as a rallying cry for rebellion in former republics The entire graph of the function f is shown in the figure below.Write the domain and range of f using interval notation. Explain how Muhammad Ali Jinnah's and Jawaharal Nehru's perspective on the proposed portion are different White supremacy is primarily an ideology. What the correct answer true or false The degree of this expression 2x+3y=4 Describe an approach to treating obesity in teens. Find the percentage of the following:20/6018/6021/6031/60 Which statement best describes the role of women at the front lines of World War I? Tomlinson Packaging Corporation began business in 2018 by issuing 30,000 shares of $5 par common stock for $8 per share and 5,000 shares of 6%, $10 par preferred stock for par. At year end, the common stock had a market value of $10. On its December 31, 2019 balance sheet, Tomlinson Packaging would report:___________a. Common Stock of $100,000b. Paid-In Capital of $150,000c. Common Stock of $200,000d. Common Stock of $160,000 g A monopoly is a market that has Group of answer choices Only one buyer. Only one seller. Many sellers who sell differentiated products. Many sellers who sell identical products. Why has April 15 come to be know as tax day ? please help me please help me Porque las enzimas actuan sobre algunas sustancias If f(x) =3x^2 +1 and g(x) = 1 -x, what is the value of (f-g) (2)? Suppose the national mean annual salary for a school administrator is $91,000 a year. A school official took a sample of 25 school administrators in the state of Ohio to learn about salaries in that state to see if they differed from the national average.77,600 76,000 90,700 97,200 90,700101,800 78,700 81,300 84,200 97,60077,500 75,700 89,400 84,300 78,70084,600 87,700 103,400 83,800 101,30094,700 69,200 95,400 61,500 68,800(a) Formulate hypotheses that can be used to determine whether the population mean annual administrator salary in Ohio differs from the national mean of $91,000.H0: 91,000Ha: > 91,000H0: > 91,000Ha: 91,000H0: 91,000Ha: < 91,000H0: < 91,000Ha: 91,000H0: = 91,000Ha: 91,000(b) The sample data for 25 Ohio administrators is contained in the file named Administrator.What is the test statistic for your hypothesis test in part (a)? (Round your answer to three decimal places.)What is the p-value for your hypothesis test in part (a)? (Round your answer to four decimal places.)p-value = (c) At = 0.05,can your null hypothesis be rejected? What is your conclusion?Reject H0. We can conclude that the mean annual administrator salary in Ohio differs significantly from the national mean annual salary.Do not reject H0. We cannot conclude that the mean annual administrator salary in Ohio differs significantly from the national mean annual salary. Reject H0. We cannot conclude that the mean annual administrator salary in Ohio differs significantly from the national mean annual salary.Do not reject H0. We can conclude that the mean annual administrator salary in Ohio differs significantly from the national mean annual salary.(d) Repeat the preceding hypothesis test using the critical value approach.State the null and alternative hypotheses.H0: 91,000Ha: > 91,000H0: > 91,000Ha: 91,000H0: 91,000Ha: < 91,000H0: < 91,000Ha: 91,000H0: = 91,000Ha: 91,000Find the value of the test statistic. (Round your answer to three decimal places.)State the critical values for the rejection rule. Use = 0.05. (Round your answer to three decimal places. If the test is one-tailed, enter NONE for the unused tail.)test statistictest statisticState your conclusion.Reject H0. We can conclude that the mean annual administrator salary in Ohio differs significantly from the national mean annual salary.Do not reject H0. We cannot conclude that the mean annual administrator salary in Ohio differs significantly from the national mean annual salary. Reject H0. We cannot conclude that the mean annual administrator salary in Ohio differs significantly from the national mean annual salary.Do not reject H0. We can conclude that the mean annual administrator salary in Ohio differs significantly from the national mean annual salary.