Prove that cos x + cos 3x + cos 5x + cos 7x = 4cos x cos 2x cos 4x

Answers

Answer 1

Step-by-step explanation:

Prove the following?

cos7x+cos5x+cos3x+cosx=4cosxcos2xcos4x

2

SEE ANSWERS

Answer

3.4/5

36

LHS=cos7x + cos5x + cos3x + cosx

=2cos[(7x+5x)/2].cos[(7x-5x)/2] + 2cos[(3x+x)/2].cos[(3x-x)/2]

[∵ cosA + cosB = 2.cos[(A+B)/2].cos[(A-B)/2]]

=2cos[(12x)/2].cos[(2x)/2] + 2cos[(4x)/2].cos[(2x)/2]

=2cos 6x.cosx+2cos2x.cosx

=2cosx(cos 6x+ cos 2x)

=2.cosx(2cos[(6x+2x)/2].cos[(6x-2x)/2]

=2.cosx(2cos4x.cos2x)

=4.cosx.cos2x.cos4x

=RHS.

hope this helps you!!!!! :))))))))


Related Questions

The students can make 6 tickets from each sheet of paper. How many sheets of paper. How many sheets of paper are needed for 125 tickets?

Answers

Answer:

20.8333333

Step-by-step explanation:

6 x 20.8333333 = 125

Condense to a single logarithm: 4 log9 11 - 4 log9 7.
O log9, (44/28)
O log9, (11/7)^4
O log9, (11/28)
log9 (44/7)

Answers

Answer: Log9,(11/7)^4

Step-by-step explanation:

according to the rules of logarithm

1)Subtraction sign(-) becomes division(÷),while addition(+)becomes multiplication (x)

2) the number in front of the log figure becomes an indices

Answer:

log9 (11/7)4

Step-by-step explanation:

got it right on the test

4.321 × 12.34 AND IF YOU ANSWER YOU GET 10 POINTS JUST PLS HELP

Answers

Answer:

53.32114

Step-by-step explanation:

whats 2 plus 2? do u know?

Answers

I think it might be 4.. I’m not sure tho

Find f(5). f(x) = x2 + 2x
Help please

Answers

Answer:

Your answer is: 15

Your equation would have f(5) = x^2 + 2x

Substitute the given value into the function and evaluate.

Step-by-step explanation:

Hope this helped ; )

The product of 3 consecutive integers is 4,896. What is the largest of the three consecutive numbers?

Answers

Answer:

18

Step-by-step explanation:

1. Try to create an equation. We can say that the first number is x and the following numbers are x+1 and x+2. That means that x*(x+1)*(x+2)=4896.

2. Solve and Simplify. x^3+3x^2+2x=4896.

3. Solve and Simplify (2) I'm assuming that you're not looking for the complex solutions, so x=16.

4. Find the 3rd number. 16+2=18

Answer: 18 is the largest number of the three

Three high school participated in a study to evaluate the effectiveness of a new computer-based mathematics curriculum. Four 24-student sections of freshman algebra were available for the study. The two types of instruction (standard curriculum, computer-based curriculum) were randomly assigned to the four sections in each of the three schools. At the end of the term, a standard mathematics achievement test was given to each of the 24 students in each section.
a. Is this study experimental, observational, or mixed experimental and observational? Why?
b. Identify important factors, factor levels, and/or factor-level combinations.
c. Classify these factors as within- or between-subjects
d. what’s the dependent measures?
e. What is the basic experiment unit of study?

Answers

Answer:

Given that;

There are three high schools, each having four sections of every 24 students

the 2 types of instructions are Standard curriculum  & computer based curriculum

a)

this study is experimental

this is because the study did not just observe the student's performance but randomly assign the performance to different techniques that have some certain control over the technique of teaching and then observe their performance afterwards

b)

-important  factors are; high schools, instruction type and scores

- Highschool has 2 levels: level one there are three high schools,  level 2 each having four sections of every 24 students

-instruction type: has one level which is  divided into two namely; standard base and computer based

Scores: doesn't have levels

c)

there are 3 schools and 4 sections  so the factor high school has between subjects components

factor instruction type also has between subjects because there are two different types available

there are 24 students in each section which are within subjects

d)

the score on the test  is the dependent measures

e)

“STUDENT” in each section is he basic experiment unit of study

If the width of a rectangle is 3x+2 and the length is 2(x+4) what is the value of x​

Answers

Answer:

 

Step-by-step explanation:

Which statement describes the inverse of m(x) = x^2 – 17x?


a. The domain restriction x ≥ StartFraction 17 Over 2 EndFraction results in m–1(x) =StartFraction 17 Over 2 EndFraction minus StartRoot x + StartFraction 289 Over 4 EndFraction EndRoot .


b. The domain restriction x ≥ StartFraction 17 Over 2 EndFraction results in m–1(x) =StartFraction 17 Over 2 EndFraction + StartRoot x + StartFraction 289 Over 4 EndFraction EndRoot .


c. The domain restriction x ≥ Negative StartFraction 17 Over 2 EndFraction results in m–1(x) =StartFraction 17 Over 2 EndFraction minus StartRoot x + StartFraction 289 Over 4 EndFraction EndRoot .


d.The domain restriction x ≥ Negative StartFraction 17 Over 2 EndFraction results in m–1(x) =StartFraction 17 Over 2 EndFraction + StartRoot x + StartFraction 289 Over 4 EndFraction EndRoot .

Answers

Given:

The function is

[tex]m(x)=x^2-17x[/tex]

To find:

The inverse of the given function.

Solution:

We have,

[tex]m(x)=x^2-17x[/tex]

Substitute m(x)=y.

[tex]y=x^2-17x[/tex]

Interchange x and y.

[tex]x=y^2-17y[/tex]

Add square of half of coefficient of y , i.e., [tex]\left(\dfrac{-17}{2}\right)^2[/tex] on both sides,

[tex]x+\left(\dfrac{-17}{2}\right)^2=y^2-17y+\left(\dfrac{-17}{2}\right)^2[/tex]

[tex]x+\left(\dfrac{17}{2}\right)^2=y^2-17y+\left(\dfrac{17}{2}\right)^2[/tex]

[tex]x+\left(\dfrac{17}{2}\right)^2=\left(y-\dfrac{17}{2}\right)^2[/tex]        [tex][\because (a-b)^2=a^2-2ab+b^2][/tex]

Taking square root on both sides.

[tex]\sqrt{x+\left(\dfrac{17}{2}\right)^2}=y-\dfrac{17}{2}[/tex]

Add [tex]\dfrac{17}{2}[/tex] on both sides.

[tex]\sqrt{x+\left(\dfrac{17}{2}\right)^2}+\dfrac{17}{2}=y[/tex]

Substitute [tex]y=m^{-1}(x)[/tex].

[tex]m^{-1}(x)=\sqrt{x+(\dfrac{189}{4}})+\dfrac{17}{2}[/tex]

We know that, negative term inside the root is not real number. So,

[tex]x+\left(\dfrac{17}{2}\right)^2\geq 0[/tex]

[tex]x\geq -\left(\dfrac{17}{2}\right)^2[/tex]

Therefore, the restricted domain is [tex]x\geq -\left(\dfrac{17}{2}\right)^2[/tex] and the inverse function is [tex]m^{-1}(x)=\sqrt{x+(\dfrac{189}{4}})+\dfrac{17}{2}[/tex].

Hence, option D is correct.

Note: In all the options square of [tex]\dfrac{17}{2}[/tex] is missing in restricted domain.

Answer:

C on edu

Step-by-step explanation:

¿Cuál es la desigualdad de 3 x - 4> 4-4-3 x

Answers

3 x - 4> 4-4-3
3x-4>-3
suma 4 a ambos lados:
3x>1
dividir 3 en ambos lados:
x>1/3

Kyle invested $ 500 and received $ 650 after three years. What had been the interest rate?

Answers

Answer:
216 2/3 : 1
1= one year

Since Kyle invested $500 and received $650 after three years, the value of Kyles's interest rate is 43.3%.

Given the following data:

Principal = $500Simple interest = $650Time = 3 years

To calculate the value of Kyles's interest rate:

Mathematically, simple interest is given by the formula:

[tex]S.I = \frac{PRT}{100}[/tex]

Where:

S.I is the simple interest.P is the principal amount.R is the interest rate.T is the time measured in years.

Making R the subject of formula, we have:

[tex]R = \frac{100S.I}{PT}[/tex]

Substituting the given parameters into the formula, we have;

[tex]R = \frac{100 \times 650}{500 \times 3}\\\\R = \frac{65000}{1500}[/tex]

Interest rate, R = 43.3%

Read more: https://brainly.com/question/22621039?referrer=searchResults

Henry buys a bag of 15 tangerines for $2.85.
Find the unit price in dollars per tangerine.
If necessary, round your answer to the nearest cent.
Please help with this

Answers

Answer:

.19 cents per tangerine

Step-by-step explanation:

.19 x 15 = 2.85

HELP ME PLSSS SOMEONE HELPP ILL GIVE BRAINLIEST

tom sold 3 cars ( a total value of $112,500) in the month of january. it is paid only by commission for its seller. he receives a commission of 7%. what is tom’s salary for the month of january?

Answers

Answer:

First multiply 112,500 times 3 (because of the 3 cars) answer should be $337,500

Then do the percentage (7%) $23,625

I believe that 23625 is the answerrr

Check the statements that are true.
A. An arithmetic sequence is a linear function whose domain is restricted to the set of non-negative integers.
B. A geometric sequence is a linear function whose domain is restricted to the set of non-negative integers.
C. An arithmetic sequence is an exponential function whose domain is restricted to the set of non-negative integers.
D. A geometric sequence is an exponential function whose domain is restricted to the set of non-negative integers.

Answers

Answer:

A and D.  

Step-by-step explanation:

A sequence is a set of the objects or numbers in a specific order. It is a function whose domain is a set of natural numbers or non-negative integers i.e. {1, 2, 3,..}

(A)

"An arithmetic sequence is a linear function whose domain is restricted to the set of non-negative integers."  

The general form an arithmetic sequence is:

[tex]a_{n}=a_{1}+(n-1)d[/tex]

The function is linear. The sequence consists of either numbers that are increasing or decreasing based on the value of d, the common difference.

So, the statement provided is True.

(D)

"A geometric sequence is an exponential function whose domain is restricted to the set of non-negative integers."

The general form an geometric sequence is:

[tex]a_{n}=a_{1}\cdot r^{n-1}[/tex]

The function is exponential. The sequence consists of either numbers that are exponentially increasing or decreasing by the factor r, the common ratio.

So, the statement provided is True.

Find the value of 45\75=5

Answers

Answer:

.6

Step-by-step explanation:

Please help 60 Points!!!!!!!! my school is glitched :C

Answers

Answer:

its the two that are glitched because its not any of the other ones

Step-by-step explanation:

Answer:

reload

Step-by-step explanation:

**PLEASE HELP THIS IS DUE TODAY** when the sun's declination is at the highest point, what direction does the sun rise and set?​

Answers

june 22 the declination reaches a maximum of 24.45° on june 22 summer solstice in the northern hemisphere and a minimum of -23.45 on december 21-22 winter solstice in the northern hemisphere. the sun, the moon, the planets and the stars all rise in the east and set in the west. and that’s because earth spins towards the east

Christopher wanted to save some money. After 4 weeks, Christopher $50, and after 9 weeks, he saved $100. What was the average amount Christopher saved per week? * A.5 B.50 C.12.5 D.10​

Answers

Step-by-step explanation:

I think 12.5 is the answer

IMPLAYER
Every day after ser daily walk, Dena drinks 1.06 liters of water. Which decimal is equivalent to 1.06?
A 1.6
O
B. 1.600
C. 1.060
D. 1.006

Answers

Answer:

C. 1.060

Explanation:

r Which decimal is equivalent to 1.06? Well, if you look at it, c. 1.060 is just 1.06 with a zero added at the end... And we all know zeros have no value. So you can technically just take off the zero at the end and have 1.06. But this is a multiple-choice so you don't get to choose whether or not to take the zero off. So yeah, the answer is c.

Please mark brainliest!

This problem illustrates the limit derivation of a Poisson distribution from Binomial distributions. Suppose an average of 66 arrivals occur during a 30 minute interval. To count arrivals, divide the 30 minute interval into nn sub-intervals. On the previous problem, you found the probability pp of one arrival during a single sub-interval for each n given. Now, compute the (estimated) probability that there will be, in fact, exactly 6 arrivals during a 30 minute interval, with each probability model:

a. Using Binomial with n=30, the chance of 6 arrivals is estimated as:__________
b. Using Binomial with n=60, the chance of 6 arrivals is estimated as:__________
c. Using Binomial with n=100n=100, the chance of 6 arrivals is estimated as:________
d. Using Poisson, the chance of 6 arrivals is estimated as:________

Required:
Use a probability calculator, and enter answers in decimal form, rounded to at least four places after the decimal.

Answers

Answer:

1. 0.1795

2. 0.1693

3. 0.1657

4. 0.1606

Step-by-step explanation:

This problem was solved using the binomial distribution

1.

N = 30

P = 6/30 = 0.2

Using binomial distribution

30C6 x 0.2⁶ x 0.8²⁴

= 593775 x 0.000064 x 0.004722

= 0.1795

2.

N = 60

P = 6/60 = 0.1

60C6 x 0.1⁶ x 0.9⁵⁴

= 50063860 x 0.000001 x 0.00338139

= 0.1693

3.

N = 100

100C6 x 0.06⁶ x 0.94⁹⁴

= 1192052400 x 0.000000046656 x 0.00297864

= 0.1657

4.

Poisson distribution was used here

e^-6(6)⁶/6!

= 0.1606

Is 4.95 a terminating decimal

Answers

Answer:

Definitely

since the definition of a terminating decimal is one that has an ending, and a Repeating decimal is one that never ends.

Step-by-step explanation:

Find the slope and y-intercept of the line
f(x) = 4x - 6

Answers

Answer:

Slope: 3/2
Y-intercept: -6

Answer:

y=mx+b m= rise/run b= y-intercept (0,b)

hope this helps

Step-by-step explanation:

A bowl of fruit contains seven pieces of fruit, including two bananas and five apples. Three pieces of fruit are chosen. What is the probability that one banana and two apples are chosen?

Answers

Answer:

[tex]\frac{4}{7}[/tex]

Step-by-step explanation:

A combination refers to the selection of objects such that order does not matter. A permutation refers to the arrangement of objects such that order do matter.

Number of bananas = 2

Number of apples = 5

One banana and two apples are chosen.

So,

probability that one banana and two apples are chosen = [tex]\frac{C(2,1)\,C(5,2)}{C(7,3)}[/tex]

[tex]C(2,1)=\frac{2!}{1!(2-1)!}=2[/tex]

[tex]C(5,2)=\frac{5!}{2!(5-2)!}=\frac{5!}{2!31} =10[/tex]

[tex]C(7,3)=\frac{7!}{3!(7-3)!} =\frac{7!}{3!4!}=35[/tex]

So,

Probability that one banana and two apples are chosen = [tex]\frac{2(10)}{35}=\frac{4}{7}[/tex]

Answer:

Or 57.14%

Step-by-step explanation:

what is the answer to the first one? pls help

Answers

Answer:

Step-by-step explanation:

14.75 - 8.85 = 5.9

5.9/2

5.9/2 sssssssssssssss

can someone tell me what my GPA is.

Answers

Answer:

probably 5.00

Step-by-step explanation:

maybe a 4.0 or higher cuz those r really good grades

Numbers with zeros
A cleaning service orders 7 large bottles and 5 small bottles of a cleaning product.
Each large bottle has 122 ounces. Each small bottle has 68 ounces.
Which is the best estimate of the total amount of cleaning product the cleaning service orders?
A 800 ounces
w
B. 1.200 ounces
C. 1,600 ounces
o
D. 2.000 ounces

Answers

B and I hope this helps

Lucy, charlie, and Michael have a total of $95 in their wallet. Charlie has $10 more than lucy. Michael has 3 times what Lucy has. How much does each have?

Answers

I don,t I wish I could help but maybe us Socratic

Help me please!!..,,

Answers

Answer:

A.

Step-by-step explanation:

1.5 x 0.1 = 0.15

0.15 inches

Dont know if this is for sure right. Hope it is.

If f(x) = 2x2 + x-1, then f(-5)
= ?

Answers

Answer:

-54

Step-by-step explanation:

(-5)^2 = -25

2(-25)+ -5 +1 =-54

Answer:

f(-5) = -2

Step-by-step explanation:

f(-5) = 2x2 + -5 -1

f(-5) = 4 - 6

f(-5) = -2

Solve each of the following equations for the missing variable.
-2.5x – 10 = 40
O x = 20
O x= -20
O 50
-50

Answers

Answer:

-20

Step-by-step explanation:

-2.5x = 40 + 10

- 2.5x = 50

x = 50/-2.5 = -20

Hi hi I hope you know I’m not doing anything right
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