write cos2x as sinx
please help with this ​

Answers

Answer 1

Answer:

[tex]\cos(2\, x) = 1 - 2\, (\sin(x))^2[/tex].

Step-by-step explanation:

Angle sum identity for cosine: [tex]\cos(a + b) = \cos(a) \, \cos(b) - \sin(a) \, \sin(b)[/tex].

Pythagorean identity: [tex](\cos(a))^{2} + (\sin(a))^{2} = 1[/tex] for all real [tex]a[/tex].

Subtract [tex](\cos(x))^{2}[/tex] from both sides of the Pythagorean identity to obtain: [tex](\sin(a))^{2} = 1 - (\cos(a))^{2}[/tex].

Apply angle sum identity to rewrite [tex]\cos(2\, x)[/tex].

[tex]\begin{aligned}&\cos(2\, x)\\ &= \cos(x + x) \\ &= \cos(x) \, \cos(x) - \sin(x)\, \sin(x) \\ &= (\cos(x))^{2} + (\sin(x))^{2}\end{aligned}[/tex].

[tex](\sin(a))^{2} = 1 - (\cos(a))^{2}[/tex] follows from the Pythagorean identity. Hence, it would be possible to replace the [tex](\cos(x))^{2}[/tex] in the previous expression with [tex](1 - (\sin(x))^{2})[/tex].

[tex]\begin{aligned}&(\cos(x))^{2} - (\sin(x))^{2}\\ &= \left[1 - (\sin(x))^{2}\right] - (\sin(x))^{2} \\ &= 1 - 2\, (\sin(x))^{2} \end{aligned}[/tex].

Conclusion:

[tex]\begin{aligned}&\cos(2\, x) \\ &= (\cos(x))^{2} + (\sin(x))^{2} \\ &=1 - 2\, (\sin(x))^{2}\end{aligned}[/tex]


Related Questions

Evaluate the function.
f(x)=2x^2+8x
Find f(−1)
PLease help!


a:-10
b:-6
c:6
d:10

Answers

The answer is d!!!!!

Answer:b

Step-by-step explanation:

The pie chart below shows the percentage of total revenue that a publisher receives from various types of publications. Use this chart to answer the questions
below.

Answers

Answer:

a. Cookbooks

b. 50%

c. 30%

Step-by-step explanation:

According To the Question,

We have a total revenue of a publisher describe in a circle (360°).

a. Now, Approximately Cookbooks & Textbooks revenue Form 180°, but textbook revenue is more than cookbooks as clearly visible in the diagram

Thus, cookbooks are less than 90°.

Now, we have to find 1/5th of total publisher revenue which is 360°/5= 72°. & the Cookbooks is nearest to 72° ( less than 90°)

So, Answer For (a) is Cookbooks  

b. Here in Diagram Clearly Visible that The Cookbooks & Textbooks Revenue Form 180° which is Approximately 50% of total Publisher's Revenue.

So, the Total Revenue Comes From Textbooks & Cookbooks is 50%.

c. Now We know the Cookbooks + Textbooks Revenue form 180° Approximately & Cookbook is approximately equal to 72° (as we solve above)

So, textbooks are 180°-72° = 108°, which is 30% of 360° ∴ 30% Revenue Come From Textbooks.

For what value of x is the rational expression below equal to zero?
20+2x
5-x
O A. -10
O B. -5
C. 10
O D. 5

Answers

Answer:

A.-10 should be the answer to the question..

The rational expression is zero at x = -10.

What is rational expression?

The ratio of two polynomials is known as a rational expression.

The given rational expression can equate to zero

[tex]\frac{20+2X}{5-X} =0[/tex]

Then, 20+2x=0

Therefore, x = (-20/2) = -10.

At x = -10, the given rational expression is zero.

To learn more about rational expression, use the link given below:

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The length of a rectangle should be 20 meters longer than 8 times the width. If the length must be
between 116 and 180 meters long, what are the restrictions for the width, z?
Write the solution set as an algebraic inequality solved for the variable

Answers

Answer:

The width of the rectangle lies between 12 and 20.

Step-by-step explanation:

Let the width of the rectangle is w.

length of the rectangle,

L = 8 w + 20

116 < L < 180

So,

116 < 8 w + 20 < 180

96 < 8 w < 160

12 < w < 20

So, the width of the rectangle lies between 12 and 20.

What is 30% of 280 passengers

Answers

Answer:

84 Passengers

Step-by-step explanation:

30/100(280)

= 3/10(280)

= 84

Answer:

84

Step-by-step explanation:

30/100x280

So 84 is the answer

HW HELP ASAP PLZZZZZ

Answers

Answer:

ur ans is here...

find the area
steps, please

Answers

Answer:

45) 35.75 sq km

46) 24.5 sq km

Step-by-step explanation:

Area of Square:

A= [tex]\frac{(base)(height)}{2}[/tex]

45) A = (11)(6.5) ÷ 2 =

46) A = (10)(4.9) ÷ 2 =

Answer:

45) [tex]35.75[/tex] [tex]km^2[/tex]

46) [tex]24.5[/tex] [tex]km^2[/tex]

Step-by-step explanation:

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

The formula to find the area of a triangle is  [tex]A=\frac{1}{2}bh[/tex] where [tex]b[/tex] stands for the base and [tex]h[/tex] stands for the height.

So, let's solve and find out the answer.

--------------->>>>

45)

[tex]A=\frac{1}{2}(11)(6.5)[/tex]

[tex]A=\frac{1}{2}(71.5)[/tex]

[tex]A=35.75[/tex]

The area of this triangle is [tex]35.75[/tex] [tex]km^2[/tex]

--------------->>>>

46)

[tex]A=\frac{1}{2} (10)(4.9)[/tex]

[tex]A=\frac{1}{2} (49)[/tex]

[tex]A=24.5[/tex]

The area of this triangle is [tex]24.5[/tex] [tex]km^2[/tex]

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

Hope this is helpful

Alejandro used a mathematical property to create two equivalent expressions.
6(x + 2) = 6x + 30
Which of the following is the missing term?
O 24
Х
O 5x
6
5

Answers

The answer is 5 hope this helps!

Mr. Jones lives in City A and drives at a constant speed to City B, which is 400 km 2 of the distance at that same away. On the way back to City A, Mr. Jones drives 5 constant speed. Then, because of rain, he decreases his speed by 20 km/h. The round trip takes 11 hours. How fast did Mr. Jones drive during the rainy part of his trip from City B to City A?​

Answers

Answer:

He traveled at 72km/hr during the rain

Step-by-step explanation:

Question is not well formatted. See comment

Given

[tex]d=400km[/tex] --- distance

[tex]t = 11hrs[/tex] --- total time

Let his speed from city A till the rain starts on his return trip be [tex]s_1[/tex]

Let his speed from city during the rain be [tex]s_2[/tex]

So:

[tex]s_2 = s_1 -20[/tex]

Required

Calculate [tex]s_2[/tex]

From the question, we understand that; he drives the whole 400 km and 2/5 of 400 km at [tex]s_1[/tex]

The distance covered during this period is:

[tex]d_1 = 400 + \frac{2}{5} * 400[/tex]

[tex]d_1 = 400 + 160[/tex]

[tex]d_1 = 560[/tex]

And the time during this period is:

[tex]t_1 = \frac{2}{5} * 11[/tex]

[tex]t_1 = 4.4[/tex]

So, the distance during the rain is:

[tex]d_2 = 2 * 400 - d_1[/tex]

[tex]d_2 = 2 * 400 - 560[/tex]

[tex]d_2 = 800 - 560[/tex]

[tex]d_2 = 240[/tex]

And the time during the rain is:

[tex]t_2 = 11 - t_1[/tex]

[tex]t_2 = 11 - 4.4[/tex]

[tex]t_2 = 6.6[/tex]

So, we have:

[tex]d_1 = 560[/tex] --- distance covered before the rain

[tex]d_2 = 240[/tex] --- distance covered when raining

[tex]s_2 = s_1 -20[/tex]

[tex]t_1 = 4.4[/tex] ---- time spent before the rain

[tex]t_2 = 6.6[/tex] --- time spent in the rain

Speed is calculated as:

[tex]Speed = \frac{distance}{time}[/tex]

Make distance the subject

[tex]distance = speed * time[/tex]

So:

[tex]d_1 + d_2 = s_1 * t_1 + s_2 * t_2[/tex]

Recall that:

[tex]s_2 = s_1 -20[/tex]

Make [tex]s_1[/tex] the subject

[tex]s_1 = s_2 + 20[/tex]

The expression [tex]d_1 + d_2 = s_1 * t_1 + s_2 * t_2[/tex] becomes:

[tex]560 + 240 = (s_2 + 20) * 4.4 + s_2 * 6.6[/tex]

[tex]800 = 4.4s_2 + 88+ 6.6s_2[/tex]

Collect like terms

[tex]6.6s_2 + 4.4s_2 = 880 - 88[/tex]

[tex]11s_2 = 792[/tex]

Solve for [tex]s_2[/tex]

[tex]s_2= \frac{792}{11}[/tex]

[tex]s_2=72km/h[/tex]

The distance and time 400 km and 11 hours as well as the speed

reduction gives the speed during the rainy part as 60 km/h.

Which method can be used to find the speed in the rain?

Based on the comment in the question, we have;

Given:

Distance between City A and City B = 400 km

Distance travelled at the same speed on his way back = [tex]\mathbf{\frac{2}{5}}[/tex] of the distance

Amount by by which his speed is reduced in the remaining [tex]\frac{3}{5}[/tex] of the distance because of rain = 20 km/h

The duration of the trip = 11 hours

Required:

How fast Mr. Jones was driving during the rainy part of his trip from City

B to City A?

Solution:

Let v represent the constant speed, we have;

[tex]Time = \mathbf{ \dfrac{Distance}{Speed}}[/tex]

The distance for which his speed is v = ([tex]\frac{2}{5}[/tex] + 1) × 400 km = 560 km

Total distance of the round trip = 400 km + 400 km = 800 km

The distance for which the speed = v - 20 = 800 km - 560 km = 240 km

Therefore, we have;

[tex]\mathbf{\dfrac{560}{v} + \dfrac{240}{v - 20}}= 11[/tex]

Which gives;

[tex]\mathbf{\dfrac{560 \times (v - 20) + 240 \cdot v}{v\times (v - 20) } } = 11[/tex]

11 × (v² - 20·v) = 560·v - 20 × 560 + 240·v

11·v² - 220·v - 560·v - 240·v + 11200

11·v² - 1020·v + 11,200 = 0

Using the quadratic formula, to solve the above quadratic equation we have;

[tex]v = \dfrac{1020 \pm\sqrt{(-1020)^2 - 4 \times 11 \times 11200} }{2 \times 11} = \dfrac{1020 \pm740 }{22} = \mathbf{ \dfrac{1020 \pm740 }{22}}[/tex]

v = 80 or v = [tex]12 . \overline{72}[/tex]

The possible value for the constant speed is therefore;

v = 80 km/h

The speed during the rain = v - 20, which gives;

The speed during the rain = 80 km/h - 20 km/h = 60 km/h

Learn more about quadratic formula here;

https://brainly.com/question/283838

How many different 5 digit natural numbers are there starting with odd numbers or ending with even numbers.

Answers

I would help you but I read another language

if marvin bought 490 soda cans and candy bars, where the ratio is 3:4, respectively, how many of each did marvin buy?

Answers

9514 1404 393

Answer:

210 soda cans280 candy bars

Step-by-step explanation:

The 3+4 = 7 ratio units represent the total of 490 snacks, so each ratio unit represents 490/7 = 70 snacks.

The number of soda cans is 3·70 = 210.

The number of candy bars is 4·70 = 280.

Marvin bought 210 soda cans and 280 candy bars.

Hallar la ecuación de la recta (2,3) y (1,-2)

Answers

Answer:

[tex]y=5x-7[/tex]

Step-by-step explanation:

the points -6/5 and -5/6 will line in which quadrant​

Answers

A negative x is to the left of the y axis and a negative y value is below the x axis. Any value to the left and below the axis’ will be in the 3rd quadrant.

Answer: 3rd quadrant

WILL MARK YOU IF YOU HELP ME !!!!

Answers

Answer:

Perpendicular bisector

Answer:

perpendicular bisector

Express in roster form. Set of B is the set of all elements x such that x is an element of natural numbers and x is a multiple of 8

Answers

Answer:  Choice F.  {8, 16, 24, 32, ...}

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

Explanation:

The set of natural numbers is {1,2,3,...} basically anything positive and a whole number.

Any multiple of 8 is of the form 8x. Since x is a natural number, the smallest it can be is x = 1 which corresponds to 8x = 8*1 = 8. So 8 is the first multiple of the set. Then 16 is next because 8x = 8*2 = 16, and so on.

That's how we end up with {8, 16, 24, 32, ...}

The three dots, or ellipses, tell the reader that the pattern goes on forever. This set is infinitely large. We wouldn't stop at 800 because we could plug in say x = 200 to get 8x = 8*200 = 1600 and that's a multiple of 8.

i need to see the steps for simplifying 3(m-5)+m​

Answers

Answer:

4m - 15

Step-by-step explanation:

a( x + y) = ax + ay

[tex]3( m - 5 ) + m\\\\3m - 15 + m \\\\4m - 15[/tex]

Answer:

4m-15

Step-by-step explanation:

Distrubite 3 through the parentheisis

3m-15+m

Collect like terms

4m-15

I can clean my apartment in two hours. My roommate could clean it in three hours. How long will it take use the clean the apartment if we work together?

Answers

Answer:

So in this question you want the average because both of y'all are working together. To take the average you want to multiply 2x3=6/2=3

3 hours if y'all work together!

Step-by-step explanation:


A circle has a circumference of 28 centimeters. If an arc subtends a central angle of 55 degrees, what is the arc length?
A.4.28 centimeters
B.26.88 centimeters
C.53.76 centimeters
D.8.56 centimeters

Answers

Answer:

s = 4.28 cm (Answer A)

Step-by-step explanation:

1) The formula for the circumference of a circle of radius r is C = 2(pi)r, and this corresponds to a full circle, with central angle 360 degrees.  

2) Here the circumference is 28 cm.  Therefore, solving for the radius involves the following calculation:   28 cm = 2(pi)r, or

r = (28 cm) / (2 pi), or (28 cm) / 6.28 = 4.46 cm.  

3) The arc length s = r(theta), when the central angle (theta) is 55 degrees, is (55/360) times the circumference of the circle:  (55/360)(28 cm), or

s = 4.28 cm (Answer A)

Two cities are 3450 miles apart. A plane leaves one of​ them, traveling towards the other at an average speed of 310 miles per hour. At the same time a plane leaves the​ other, traveling towards the​ first, at an average speed of 380 miles per hour. How long will it take them to​ meet?

Answers

Answer:

5 hours.

Step-by-step explanation:

let they meet after t hours.

310t+380t=3450

690t=3450

69t=345

t=345/69=5

Crhistine paid $633.68 for a handbag the sales tax in her state is 6.5% what was the price of the hand bag before the sales tax was added

Answers

Answer:

Step-by-step explanation:

X * (1.065) = $633.68

X = $633.68/1.065

X= $595.00

The price of the handbag before the sales tax was added is $595

What is sale tax?

A sales tax is a tax paid to a governing body for the sales of certain goods and services. Usually laws allow the seller to collect funds for the tax from the consumer at the point of purchase.

Given that, Christine paid $633.68 for a handbag the sales tax in her state is 6.5%

Let the cost of the handbag before sales tax be x,

Therefore,

x + 6.5% of x = 633.68

x + 6.5 / 100 × x = 633.68

x(1 + 6.5 / 100) = 633.68

x(106.5 / 100) = 633.68

x = 633.68 × 100 / 106.5

x = 595

Hence, the price of the handbag before the sales tax was added is $595

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Two parallel lines, e and f, are crossed by two transversals.

What is the measure of <15
m<15 = 77°
m< 15 = 83°
m<15 = 93°
m<15= 97°

Answers

9514 1404 393

Answer:

  ∠15 = 97°

Step-by-step explanation:

At any given transversal of parallel lines, all obtuse angles are congruent, and all acute angles are congruent. Obtuse angle 15 is congruent to the one market 97°.

  ∠15 = 97°

Which rules of exponents will be used to evallate this expression? Select three options.

Answers

I need the answer choices and the expression you’re referring to

Figure ABCD is a rectangle find the value of x

Answers

Answer:

Espanol la vecsu

Step-by-step explanation:

Answer:

x = 1

Step-by-step explanation:

The diagonals of a rectangle bisect each other , so

DE = EB , that is

7x - 1 = 2x + 4 ( subtract 2x from both sides )

5x - 1 = 4 ( add 1 to both sides )

5x = 5 ( divide both sides by 5 )

x = 1

HELP ME PLSSSSSS

if f(x) = 2x-3/5 , which of the following is the inverse of f(x)?

Answers

The answer is (5x+3)/2 . So it’s A .

Find the volume of this rectangular pyramid.
Be sure to include the correct unit in your answer.
6 m
3 m
9 m

Answers

Answer:

54 m^3

Step-by-step explanation:

this is the answer = 54 m^3

Volume of the rectangular pyramid will be 54[tex]m^{3}[/tex].

What is Rectangular Pyramid?

Rectangular pyramid has 5 faces where one face is rectangular which is at bases and other 4 faces are triangular which is connected at the one point .

How to calculate the volume of the rectangular pyramid?

If we assume that l is the length of the base and b is the width of the base and h is height of the rectangular pyramid then we can calculate the volume of the rectangular pyramid using the formula stated below

                 Volume of the rectangular pyramid = V=  (1/3)×l×b×h

According to the asked question

l = 6m

b = 3m

h = 9m

then we can calculate the volume of the rectangular pyramid by using the above formula

= V=  (1/3)×l×b×h

= (1/3)×6m×3m×9m

= 54[tex]m^{3}[/tex]

Learn more about volume of the rectangular pyramid

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Will mark BRAINLIEST!! This is pt.2

Answers

Answer:

See below.

Step-by-step explanation:

Problem 3.

1. <3, <4

Given

2. <1, <2

Given

3. KG

Congruence of segments is reflexive.

4. HKG, LKG

ASA

Problem 4.

1. MR, OR

Given

2. PR, NR

Given

3. <2

Vertical angles are congruent.

4. MPR, ONR

SAS

Xác suất xảy ra môt sự kiện là 0.3. Xác suất để sự kiện đó không xảy ra là?

Answers

Câu trả lời:

0,7

Giải thích từng bước:

Xác suất để một sự kiện xảy ra = 0,3

Cho sự kiện = A

P (A) = 0,3

Xác suất mà sự kiện không xảy ra có thể thu được bằng cách sử dụng quy tắc bổ sung;

P (A ') = 1 - P (A)

Vì thế,

P (A ') = 1 - 0,3 = 0,7

27/7n > 4/3 select all the value of n that make the inequality true

A. 2/5
B. 1/5
C.1
D.2/9
E. 3/2

Answers

Answer:

A ajjajsjsjsjajsiyisisksksk

Answer: D

Step by step explanation:

Simplify the expression √(4-1)^2+(3+1)^2 using the order of operations.

Answers

Answer:

[tex]\sqrt{\left(4-1\right)^2}+\left(3+1\right)^2[/tex]

[tex]\longmapsto \sqrt{(4-1)^2} =3[/tex]

[tex]\longmapsto (3+1)^2=4^2[/tex]

[tex]\hookrightarrow 3+4^2[/tex]

[tex]\hookrightarrow 4^2=16[/tex]

[tex]\hookrightarrow 3+16[/tex]

[tex]\hookrightarrow 19\checkmark[/tex]

hope it helps

Answer:

5

Step-by-step explanation:

Given :

[tex]\sqrt{(4-1)^{2} +(3+1)^{2} }[/tex]

Now,

[tex]\sqrt{(3^{2} )+4^{2} } \\\sqrt{9+16}\\\sqrt{25} \\5[/tex]

Answer of the given expression will be 5.

199 rounded up to the nearest hundred​

Answers

Answer:

199

Step-by-step explanation:

Answer:

It would be 200 because 199 is closer to 200 rather than 100.

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