Verify that 1 + cos 2 theta / 2 cos theta = cos theta is an identity

Answers

Answer 1

Answer and Step-by-step explanation:

We want to verify that (1 + cos(2θ)) / 2cos(θ) = cos(θ).

Let's focus on the left side. Look at cos(2θ). This is an identity, so remember that cos(2θ) = cos²θ - sin²θ. Also, look at the 1. Remember that sin²θ + cos²θ = 1, so plug both of these expressions into our equation:

(1 + cos(2θ)) / 2cos(θ) =? cos(θ)

((sin²θ + cos²θ) + (cos²θ - sin²θ)) / 2cos(θ) =? cos(θ)

2cos²θ / 2cosθ =? cosθ

cosθ = cosθ

Thus, we have proved this is an identity.

Answer 2

Answer:

(1 + cos(2theta))/2cos(theta)

cos(2theta) = 2cos²(theta) - 1

(1 + 2cos²(theta) - 1)/2cos(thetal

2cos²(theta)/2cos(theta)

cos(theta)


Related Questions

On circle OOO below, the measure of \stackrel{\LARGE{\frown}}{FJ} FJ ⌢ F, J, start superscript, \frown, end superscript is 84^\circ84 ∘ 84, degrees. The measure of \stackrel{\LARGE{\frown}}{GH} GH ⌢ G, H, start superscript, \frown, end superscript is 76^\circ76 ∘ 76, degrees. What is the measure of \angle HKJ∠HKJangle, H, K, J?

Answers

Answer:

100°

Step-by-step explanation:

The angle between chords is the average of the intersected arc angles.

∠FKJ = ½ (84° + 76°)

∠FKJ = 80°

∠HKJ is supplementary to ∠FKJ.

∠HKJ = 180° − 80°

∠HKJ = 100°

The measures of the angles of a triangle are 25 degrees, 87 degrees, and 68 degrees. Is the triangle acute, right, or obtuse?

Answers

Answer:

their all less than 90 degress so its acute

Step-by-step explanation:

Pls answer the last question thank you! Number 5.

Answers

Answer:

1/2 x 4/1 x 2/1 = 4

4th should be 1/6 btw

Step-by-step explanation:

Answer:

Step-by-step explanation:

We'll say the fraction is 4 1/2 so: The length is 6 blocks the width is 2 blocks and we'll say the height is 3 blocks so the length would be 27 the width is 9 and the height is 13 1/2 now 27*9*13 1/2=3280 1/2

(you might have to draw this cube just sayin idk exactly what it wants)

Some people take the early retirement option at age 62. According to the Social Security Administration, if you retire at age 62, your retirement benefits will be permanently reduced by 25%. If your monthly benefit, at full retirement age (67), would have been $1300 per month, and you retire at age 62, how much would you lose in total annual income over one year?

Answers

Answer:

$3900.

Step-by-step explanation:

If retirement is taken at the age of 67 years, income  = $1300 per month.

% Loss, if retirement taken at the age of 62 years = 25% per month

Loss in dollars per month if retirement taken at the age of 62 years = 25% of Monthly income if retirement is taken at the age of 67 years

[tex]\Rightarrow \dfrac{25}{100} \times 1300\\\Rightarrow \dfrac{1300}{4}\\\Rightarrow 325 \$[/tex]

We know that there are 12 months in an year.

So, annual loss in total annual income over one year:

Loss in dollars per month [tex]\times[/tex] 12 :

325 [tex]\times[/tex] 12 = 3900$

Answer: $3,900

Step-by-step explanation:

What you usually make:

$1300 * 12 months = $15600

What you make with the cut:

$1300 * 0.75 = $975

* 12 months = $11700

15600-11700 = $3900

Javier is 175% heavier than his brother. If Javier’s brother weighs 80 pounds, how much does Javier weigh?

Answers

Answer:

140

Step-by-step explanation:

175% of 80 = 140

The average mark of candidates in an aptitude test was 128.5 with a standard deviation of 8.2.Three scores extracted from the test 148,102,152,what is the average of the extracted scores that are extreme values(outlier).​

Answers

Answer:

Step-by-step explanation:

Hello!

The variable of interest is

X: mark obtained in an aptitude test by a candidate.

This variable has a mean μ= 128.5 and standard deviation σ= 8.2

You have the data of three scores extracted from the pool of aptitude tests taken.

148, 102, 152

The average is calculated as X[bar]= Σx/n= (148+102+152)/3= 134

I hope this helps!


You roll a six-sided number cube (die). What is the BEST answer for the probability that the number rolled is between 1 and 6, inclusive?
A) certain
B) unlikely
C) impossible
D) very likely

Answers

Answer: It is A certain.

Step-by-step explanation:

Because all the numbers on a six-sided cube is between 1 and 6 so it is certain or 100/100 that the number will land on a number between 1 and 6.

Solve.
A European swallow flies about 12 meters in 1 second.
How many kilometers could it fly in 15 minutes?
It could fly |​

Answers

Answer:

It could fly 10,8 kilometers.

Step-by-step explanation:

The European swallow fly speed is 12 meters per second.

We have to calculate how many kilometers it could fly in 15 minutes.

This can be calculated using the equivalent factors for each of the units:

- 1 km is equivalent to 1,000 meters.

- 1 minute is equivalent to 60 seconds.

We know that the distance travelled by the fly is the product of the speed and the time, so we have:

[tex]D=v\cdot t\\\\\\D=12\,\dfrac{m}{s}\cdot15\, min\\\\\\D=12\,\dfrac{m}{s}\cdot(\dfrac{1\,km}{1,000\,m})\cdot15\, min\cdot (\dfrac{60\,s}{1\,min})\\\\\\D=\dfrac{12\cdot 15\cdot 60}{1,000}\,km=\dfrac{10,800}{1,000}\,km\\\\\\D=10,8 \,km[/tex]

A hot dog stand sells hot dogs for $3 each, but each hot dog costs $1.50 to make. Each month, the hot dog stand pays $800 in rent and $1,200 in employee wages. If the hot dog stand sells 3,120 hot dogs in a month, how much will the hot dog stand earn in profit?

Answers

Answer:

$2680

Step-by-step explanation:

3.00-1.50= 1.50 profit per hotdog

1200+800=2000 expenses

1.50 (3120) = 4680

4680-2000=

2680 in profit

Round 0.782 with 7 being the underlined digit

Answers

i think the answer is 1.92

volume ....................

Answers

Answer:

360 cm^2

Step-by-step explanation:

length x width x height

6 x 6 x 10

Answer:

360cm^3

Step-by-step explanation:

V=L*W*H

V=6*6*10

V=36*10

V=360

The points (8.1) and (8, 11) lie on a circle with a radius of 5. Find the center of the circle

Answers

Answer:

(8, 6)

Step-by-step explanation:

First, we find the distance between the two points.

Both have the same x-coordinate, 8, so the distance is simply the difference in y.

|11 - 1| = 10

The distance between the points is 10.

Since the radius of the circle is 5, the greatest distance between two points on the circle is 10, and the two points must be the endpoints of a diameter.

The midpoint of a diameter is the center of the circle.

(1 + 11)/2 = 12/2 = 6

The center o the circle is (8, 6).

Plz help ..............!!!!!

Answers

Answer:

1.8

is the median

Answer: 1.8

Step-by-step explanation: 1.8 is the median

A car can travel 480 miles on a full tank of petrol. The tank holds 60 litres. A driver fills the tank and sets off on a journey. How many litres of petrol will be left when the car has travelled 360 miles?

Answers

Answer:

15 liters

Step-by-step explanation:

60/480= 0.125

0.125*360= 45

60-45= 15

An mp3 player is on sale for 30% off the regular price of $39.98. How much is the discount?

Answers

Answer:

$27.98

Step-by-step explanation:

100 - 30 in price %=70%

Price will be 70% of original regular price

$39.98 * .7 = answer

Answer:

Discount is $11.99

Total is now $27.99

Step-by-step explanation:

To find the discount, you find out what 30% is of 39.98, so you multiply

39.98 x 30%(or .3) = 11.994

39.98- 11.99= 27.99

how many square feet of of outdoor carpet will we need for this hole?

Answers

Answer:

To convert the feet to square feet we have to multiply the length by the width. In which, we should get the answer as well.

Our length is 2ft, since it's a rectangle the other side is 2ft as well.

The width is 3ft, and the other half is 3ft.

So, basically to get the area of the hole, it'd be 3*2=

Which, it's 6sq ft.

Step-by-step explanation:The actual answer is 36. If I am wrong i am sorry ;3

Ameeta finished 12 math problems. David finished 3 times as many. How many more math problems did David finish than Ameeta?

Answers

Answer:

24

Step-by-step explanation:

Ameeta = 12 math problems.

David =12×3=36 math problems

So 36-12=24

Answer:

12

David's

3 times longer

comparison problem

Step-by-step explanation:

got right on edge

plzz help its timed ill give brainliest

Answers

First set the days to hours. Since there are 24 hours in a day you can do 197 x 24 = 4728 hours. Take the distance (48688630 miles), to get to miles per hour you do 48688630 : 4728 = 10297,933 = 10298 so B is the answer.

Giving brainliest to CORRECT answer.

Answers

b i think .. i’m not sure

Answer:

A. 2

Step-by-step explanation:

[tex] y = 16x^2 - 8x + 1[/tex] is a quadratic function, hence on solving it will give two zeros, therefore graph of the function will intersect x axis in two points.

ASAP PLEASE
simplify the equation​

Answers

Answer:

Option A is correct

Step-by-step explanation:

a^(6/4) = a^(3/2)

b^(4/4) = b

c^(8/4) = c^2

Hope this helps!

:)

What’s the correct answer for this?

Answers

Answer:

D.

Step-by-step explanation:

A horizontal translation will move the first triangle a little to the right and then after the vertical translation the triangle will move downwards and will fit into the other triangle thus we will know that the two triangles are congruent.

Please help ASAP! I will mark Brainliest! Please answer CORRECTLY! No guessing! CHECK ALL THAT APPLY

Answers

Step-by-step explanation:

D.12

A.26

........................

Answer:

D and A

Step-by-step explanation:

D= 132

A is larger than 132

John and Ellen bought a big pizza. Ellen are 2/4 of the pizza and John ate 1/3 of pizza. How much did they eat all together? How much was left over? ( hint 12 is the lowest common denominator)

(I put 1/4 but it said it was wrong:/) pls help h

Answers

Answer:

Pizza eaten together: 5/6,

Pizza left over: 1/6

Step-by-step explanation:

~ If Ellen ate 2/4th of the pizza and John ate 1/3 of the pizza, provided that the pizza counts as a whole ( 1 )... ~

1. Let us simplify 2/4th to be ⇒ 1/2, through simple algebra

2. To see how much they ate together we would neglect that the pizza counts as a whole but simply add 1/2 by 1/3rd.

3. Through simple algebra: 1/2 + 1/3 = 3/6 + 2/6 = Pizza eaten together: 5/6

4. Now to find out how much pizza was left over, we would need the fact that a pizza ⇒ 1 whole. It would be that 1 - 1/2 - 1/3 ⇒ Pizza left over, through the Partition Postulate. In fact, the pizza left over would simply be 1 whole - the pizza eaten together ( 5/6 ).

5. Through algebra: 1 - 1/2 - 1/3 = 1 - 5/6 = Pizza left over: 1/6

Answer:

How much did they eat all together? 5/6

How much was left over? 1/6

[tex] \\ [/tex]

Step-by-step explanation:

How much did they eat all together?

[tex] \frac{2}{4} + \frac{1}{3} \\ = \frac{6}{12} + \frac{4}{12} \\ = \frac{10}{12} \\ = \frac{5}{6} [/tex]

[tex] \\ [/tex]

How much was left over?

[tex] 1 - \frac{5}{6} \\ = \frac{6}{6} - \frac{5}{6} \\ = \frac{1}{6} [/tex]

hurry plz im timed. i have 20 minutes left
Which shows how the distributive property can be used to evaluate 7 times 8 and four-fifths?
56 + StartFraction 28 over 5 EndFraction = 56 + 5 and three-fifths = 61 and three-fifths
56 times StartFraction 28 over 5 EndFraction = StartFraction 1568 over 5 EndFraction = 313 and three-fifths
15 + (StartFraction 35 over 5 EndFraction + four-fifths) = 15 + StartFraction 39 over 5 EndFraction = StartFraction 75 over 5 EndFraction + StartFraction 39 over 5 EndFraction = StartFraction 114 over 5 EndFraction = 22 and four-fifths
15 times (StartFraction 35 over 5 EndFraction + four-fifths) = 15 times StartFraction 39 over 5 EndFraction = StartFraction 15 over 1 EndFraction times StartFraction 39 over 5 EndFraction = StartFraction 585 over 5 EndFraction = 117

Answers

Answer:

First one:

56 + StartFraction 28 over 5 EndFraction = 56 + 5 and three-fifths = 61 and three-fifths

Step-by-step explanation:

7 × 8⅘

7(8) + 7(4/5)

56 + 28/5

56 + 5 + 3/5

61 3/5

Answer:

its A

Step-by-step explanation:

56 + StartFraction 28 over 5 EndFraction = 56 + 5 and three-fifths = 61 and three-fifths

and pls mark me as brainliest if this is correct! :D

Which unit would be best for measuring the thickness of a coin?
kilometer
()) centimeter
meter
)) milli​

Answers

Answer:

Since 1 mm = . 03937 inches, mm would seem to be the units appropriate for defining the thickness of a coin measuring 2 units.

Step-by-step explanation:

Marcus has a life insurance policy that will pay his family $35,000 per year if
he dies. If interest rates are at 2.5% when the insurance company has to pay,
what is the amount of the lump sum that the insurance company must put
into a bank account?
O
A. $1 million
O
B. $350,000
O
C. $1.4 million
O
D. $3.5 million

Answers

The correct answer is $1.4 million

The insurance company must put $1.4 million into a bank account.

What is insurance?

Insurance is a way to manage your risk. When you buy insurance, you purchase protection against unexpected financial losses. The insurance company pays you or someone you choose if something bad happens to you.

Given that, Marcus has a life insurance policy that will pay his family $35,000 per year if he dies. the interest rates are at 2.5%, we need to find the amount of the lump sum that the insurance company must put into a bank account,

Considering that the interest is Simple interest,

So, SI = PRT / 100

Here, the interest is 35000, P we need to find, r = 2.5 and T = 1

35000 = 2.5P/100

3500000 = 2.5P

P = 1400000

P = 1.4 millions

Hence, the insurance company must put $1.4 million into a bank account.

Learn more insurance click;

https://brainly.com/question/27822778

#SPJ7

Bob wants to go to the movies with his friends. The movie theater charges $ 8 per ticket. Bob's friends reserve $ 48.00 worth of tickets in advance. How many people in total can attend the movie?

Help with steps if u love ur mama

Answers

Answer:

6 people can attend the movie with ticket worth of $ 48 if each ticket costs $ 8.

Step-by-step explanation:

1 ticket costs $ 8 then divide $ 48 to find how many tickets worth $8 are there.

[tex]48 \div 8 = 6[/tex]

Describe each pattern formed. Find the next three terms. 4,8,16,32

Answers

Answer:

The pattern is multiplying by 2.

Next three terms: 64,128,256

Step-by-step explanation:

4,8,16,32

To get from 4 to 8 we can multiply by 2.

To get from 8 to 16 we can multiply by 2.

To get from 16 to 32 we can multiply by 2.

So the pattern is multiplying by 2.

To find the next three terms:

32*2=64

64*2=128

128*2=256

Suppose the round-trip airfare between Philadelphia and Los Angeles a month before the departure date follows the normal probability distribution with a mean of $387.20 and a standard deviation of $68.50. What is the probability that a randomly selected airfare between these two cities will be between $325 and $425?

Answers

Answer:

52.74% probability that a randomly selected airfare between these two cities will be between $325 and $425

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

[tex]\mu = 387.20, \sigma = 68.50[/tex]

What is the probability that a randomly selected airfare between these two cities will be between $325 and $425?

This is the pvalue of Z when X = 425 subtracted by the pvalue of Z when X = 325. So

X = 425

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{425 - 387.20}{68.50}[/tex]

[tex]Z = 0.55[/tex]

[tex]Z = 0.55[/tex] has a pvalue of 0.7088

X = 325

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{325 - 387.20}{68.50}[/tex]

[tex]Z = -0.91[/tex]

[tex]Z = -0.91[/tex] has a pvalue of 0.1814

0.7088 - 0.1814 = 0.5274

52.74% probability that a randomly selected airfare between these two cities will be between $325 and $425

Using equivalent ratios, which statements are true about the cost per magnet? Check all that apply.

The cost of 2 magnets is $1.

The cost of 9 magnets is $3.

The cost of 10 magnets is $3.

The cost of 4 magnets is S2

The cost of 6 magnets is $2.

The cost of 3 magnets is $1.

Answers

Answer:

The true statements are:

The cost of 9 magnets is $3.

The cost of 6 magnets is $2.

The cost of 3 magnets is $1.

Step-by-step explanation:

equivalents ratios are two or more ratios that express the same relationship between the numbers involved. In order to calculate the equivalent ratios that are equal, when the numbers involved are divided, they ought to give the same result. In the answer chosen above the ratios in each case are equivalent because:

if the cost of 9 magnets is $3;

9 magnets = $3

∴ 1 magnet = 3/9 = $ 1/3 = 1:3

if the cost of 6 magnets is $2;

6 magnets = $2

1 magnet = 2/6 = $1/3 = 1:3

if the cost of 3 magnets is $1;

3 magnets = $1

∴ 1 magnet = $ 1/3 = 1:3

From the answers obtained, the equivalent ratio of 1 : 3 is the same in all case.

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