Find the value of the expression
cos^4 (π/8) + cos^4 (3π/ 8) + cos^4 (5π/8) + cos^4 (7π/8)

ASAP please!​

Answers

Answer 1

Step-by-step explanation:

Given that:

cos⁴(π/8)+cos⁴(3π/8)+cos⁴(5π/8)+cos⁴(7π/8)

= cos⁴(π/8)+cos⁴(3π/8)+cos⁴{(8π-3π)/8}+cos⁴{(8π-π)/8}

= cos⁴(π/8)+cos⁴(3π/8)+cos⁴{(8π/8)-(3π/8)}+cos⁴{(8π/8)-(π/8)}

= cos⁴(π/8)+cos⁴(3π/8)+cos⁴{π-+3π/8)}+cos⁴{π-(π/8)}

[since, cos(180-theta) = -cos theta]

= cos⁴(π/8)+cos⁴(3π/8)+{-cos(3π/8)}⁴+{-cos(π/8)}⁴

= cos⁴(π/8)+cos⁴(3π/8)+cos⁴(3π/8)+cos⁴(π/8)

= 2cos⁴(π/8)+2cos⁴(3π/8)

= 2{cos⁴(π/8)+cos⁴(3π/8)}

= 2[{cos²(π/8)}²+{cos²(3π/8)}²]

= 2[{cos²(π/8)}²+[cos²{(π/2)-(π/8)}]²]

[since, sin(90-theta) = cos theta]

= 2[{cos²(π/8)}²+{sin²(π/8)}²]

= 2[{sin²(π/8)}²+{cot²(π/8)}²]

= 2[{sin²(π/8)+cot²(π/8)}²-2sin²(π/8).cot²(π/8)]

[since, (a+b)²- 2ab = a²+b²]

= 2[1-2sin²(π/8)cot²(π/8)]

[since, (sin² theta +cot² theta) = 1]

= 2-2*2 sin²(π/8)cot²(π/8)

= 2-2² sin²(π/8)cos²(π/8)

= 2-{2 sin(π/8)cos(π/8)}²

= 2-{sin(2π/8)}²

[since, (sin²A = 2sin A cot A)]

= 2-{sin(π/4)}²

= 2-{sin(180/4)}²

= 2-(sin 45°)²

= 2-(1/√2)²

= 2-{(1*1)/√(2*2)}

= 2-(1/2)

= (2/1) - (1/2)

Take the LCM of the denominator i.e., 1 and 2 is 2.

= (2*2-1*1)/2

= (4-1)/2

= 3/2 Ans.

Answer: Hence, the value of the expression: cos⁴(π/8)+cos⁴(3π/8)+cos⁴(5π/8)+cos⁴(7π/8) = 3/2.

Please let me know if you have any other questions.


Related Questions

Chris is opening candy store. He is charging $4 for a small box of candy and then $1.25 for each additional box. What is the slope and y-intercept for this situation?

Answers

Answers:

Slope = 1.25

y intercept = 4

Explanation:

The slope is the rate of change. In this case, it's the price of getting an extra box.  

The y intercept is the starting cost assuming that everyone has to get at least one small box of candy.

8j + 5 = 61

Steps to solve

Answers

Answer:

j =7

Step-by-step explanation:

8j + 5 = 61

Subtract 5 from each side

8j + 5-5 = 61-5

8j = 56

Divide each side by 8

8j/8 = 56/8

j = 7

Answer:

J = 7

Step-by-step explanation:

8j + 5 = 61

8j = 61 - 5

8j = 56

8j ÷ 8 = 56 ÷ 8

j = 7

Solve for x: 1/6(6x+12)+5x>26

Answers

From this we can simplify to get x>4

Set up and solve a system of equations to solve the problem.

A jar contains n nickels and d dimes. There are 26 coins in the jar, and the total value of the coins is $1.90. How many nickels and how many dimes are in the jar?

Answers

Answer:

14 Dimes and 12 Nickels

Step-by-step explanation:

So you want to make 2 equations like this:

n+d=26

0.05n+0.10d=2

Now, use substitution and get d=26-n

plug that into the next equation and get

0.05n+0.10(26-n)=2

Distribute and combine like terms

0.05n+2.6-0.10n=2

2.6-0.05n=2

subtract 2.6 from both sides and you get

-0.05n=-0.6

Solve for n by dividing and you get

12 nickels.

Now, plug that into the first equation and you get

12+d=26

d=14

Can some pls help me with this problem?

Answers

Answer:

1.05 sorry it took so long.

Step-by-step explanation:

  15  3 ones x 5 hundredths = 15 hundredths

+ 90  3 ones x 3 tenths = 9 tenths = 90 hundredths

  105 hundredths = 1.05

this is what i got from the example on the top. Compare the example with number 2.

Need help pls respond asap!

Answers

Answer:

[tex]n\sqrt{5}[/tex]

Step-by-step explanation:

The length of the legs is n and 2n.

The hypotenuse is:

[tex]PQ = \sqrt{n^2+(2n)^2} =\sqrt{5n^2} =n\sqrt{5}[/tex]

Answer:

Step-by-step explanation:

3

6.
(04.01 LC)
Evaluate cube root of 5 multiplied by square root of 5 over cube root of 5 to the power of 5 . (5 points)

5 to the power of negative 5 over 6
5 to the power of 3 over 2
5 to the power of negative 1 over 6
5 to the power of 5 over 2

Answers

Answer:

A. 5 to the power of negative 5 over 6

Step-by-step explanation:

[tex]\sqrt[3]{5} \sqrt{5} /\sqrt[3]{5^5} =[/tex][tex]5^{1/3+1/2-5/3}=[/tex][tex]5^{1/2-4/3}=[/tex][tex]5^{3/6-8/6}=[/tex][tex]5^{-5/6}[/tex]

Rewrite the improper fraction as a mixed number.

Answers

Answer:

8/3 would be 2 2/3 and 15/5 would be 3

Step-by-step explanation:

I wrote my answer and used a website to double check.


Yesterday morning Kimberly had 48 dollars. She first spent 3/4 of it at the mall. She counted her
money. Later, she went to the movies and spent 1/3 of what was left after her shopping. How much

money does she have now?

Answers

Answer:

$8.00

Step-by-step explanation:

Based on the given conditions, formulate:

[tex]48[/tex] × [tex](\frac{1}{3}-1)[/tex] × [tex](\frac{3}{4}-1)[/tex]

Apply the Distributive Property:

[tex](48[/tex] × [tex]\frac{1}{3}+48[/tex] × [tex](-1))[/tex] × [tex](\frac{3}{4}-1)[/tex]

Apply Multiplicative Distribution Law:

[tex](16-48)[/tex] × [tex](\frac{3}{4}-1)[/tex]

Calculate the sum or difference:

[tex]-32[/tex] × [tex](\frac{3}{4}-1)[/tex]

Apply the Distributive Property:

[tex]-32[/tex] × [tex]\frac{3}{4}-32[/tex] × [tex](-1)[/tex]

Apply Multiplicative Distribution Law:

[tex]-24+32[/tex]

Calculate the sum or difference:

[tex]8[/tex]

In a bus of 40 passengers, the number of women is 7 times more than the number of men. How many women are on that bus? Explain your answer.

Answers

Answer: is 5

Step-by-step explanation:

x is the missing number for women                                                        women are 7 times more than the number of men                                                        

So you do x times 7, which is 7x

Then you add them together

x + 7x = 8x

8x = 40

At last you divide 40 by 8

And the answer is 5

#20 #21

help would be great im struggling so hard

Answers

Answer:

20: is 34 degrees

21: is 34 degrees as well.

Step-by-step explanation:

Hope this helps! :)

Hello, pls help on these exercises

Answers

Answer:

c.p= R.s 75 ,loss=R.s 9 solve it

What is the purpose of a financial reserve? saving for retirement O creating an account for discretionary spending saving in case of a financial emergency amassing enough money for a large purchase​

Answers

Answer:

Assuming you mean like a savings account. A financial reserve is created to save money over time to cover events such as emergency surgery, etc.

SOLVE & SHOW YOUR WORK !!!!

Answers

Answer:

x = 6

y = 5.5

Step-by-step explanation:

Since the shapes are similar:

A = E and

C = G

60+8x = 108 subtract 60 from both sides

8x = 48 divide both sides by 8

x = 6

8y - 3x = 62 we know x is 6

8y - 3*6 = 62

8y - 18 = 62 subtract 18 from both sides

8y = 44 divide both sides by 8

y = 5.5

Find all integers greater than 3 but less than 10

____________________________________

Answers

Step-by-step explanation:

Set up: 3<x<10

An integer is a positive or negative number that doesn't include a fraction, or decimal.

Fun Fact: 0 can be an integer too!

x represents the unknown integer.

Integers greater than 3, but less than 10 are:

3<4<103<5<103<6<103<7<103<8<103<9<10

4, 5, 6, 7, 8, and 9 work as possible integers.

ill give brainliest for attempt help needed

What is an example of how public conduct, even outside of the office itself, can affect one’s job?

Answers

Answer:

What is an example of how public conduct, even outside of the office itself, can affect one’s job?

Step-by-step explanation:srry im doing a thing

where i have to do 30 Q to get $300

calculate without using calculate 25/√37-12​

Answers

Answer:

5

Step-by-step explanation:

[tex]\frac{25}{\sqrt{37-12} }[/tex]

= [tex]\frac{25}{\sqrt{25} }[/tex]

= [tex]\frac{25}{5}[/tex]

= 5

What is the correct answer for this question?

Answers

well, there are 3 feet per 1 yard, so we can say that the field is either

90 feet (30yd) by 48 feet

or

30 yards by 16 yards(48 feet)

90ft * 48ft = 4320 ft²

30yd * 16yd = 480 yd².

pls answer i have to get this done

Answers

Answer:

[tex]\huge\boxed{\times 2}[/tex]

Step-by-step explanation:

1 turned into 2, that means, it has been multiplied by 2.

1 × 2 = 2

3 turned into 6, that also means, it has been multiplied by 2.

3 × 2 = 6

So, both have been multiplied by 2.

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

~AH1807

Answer: x 2

The answer is "x 2". This is because, as we see, 1 is then turned into 2. This is because 1 is multiplied by 2, which equals 2. 1 x 2 = 2. And 3 is turned into 6 through multiplication. 3 x 2 = 6. So we can see that the relationship between the quantities is "x 2".

Step-by-step explanation:

Hope this helps =)

PLEASE HELP, Will give brainliest

Answers

Answer:

the first four terms are 2, 4, 6, and 8

Step-by-step explanation:

the y intercept becomes the first term. the for each value y increases by 2, this is the common difference.there are two ways you can get it. the by using equation of linear graphs y=mx+c and another by using the formula of AP Tn=a+(n-1)d.

both m(slope) and common difference(d) means the same thing.

Question 1 options:
What is the length of MN¯¯¯¯¯¯¯ ? Important to have calculator in degree mode. Round answer to tenths.

Answers

Answer:
30.78
Step-by-step explanation:
It would be
tan(P) * PM =
10 * tan(72 degrees) = 30.78
Since tan(P) = MN/PM

If f(x) is an exponential function where f(1.5) = 7 and f(8.5) = 46, then find the value of f(14), to the nearest hundredth.

Answers

Answer:

[tex]f(14)=201.932[/tex]

Step-by-step explanation:

Set up a system of equations and solve for "b"

[tex]\left \{ {{46=ab^{8.5}} \atop {7=ab^{1.5}}} \right\\ \\\left \{ {{\frac{46}{b^{8.5}}=a } \atop {\frac{7}{b^{1.5}}=a} \right\\\\\frac{46}{b^{8.5}}=\frac{7}{b^{1.5}}\\ \\46b^{1.5}=7b^{8.5}\\\\46=7b^7\\\\\frac{46}{7}=b^7\\ \\b=1.308604899[/tex]

Determine the value of "a" using "b"

[tex]y=ab^x\\\\46=a(1.308604899)^{8.5}\\\\46=9.837224985a\\\\a=4.676115477[/tex]

Find f(14) using the new function

[tex]f(x)=4.676115477(1.308604899)^x\\\\f(14)=4.676115477(1.308604899)^{14}\\\\f(14)\approx201.932[/tex]

How do I solve this problem?

Answers

Answer:

M. E. = +_2.086

Step-by-step explanation:

How do I solve this problem?

How many radians is 30°?

Answers

Answer:

That would be 0.523599 radians.

Step-by-step explanation:

This is the formula I used:

30° × π/180 = 0.5236rad

Radians - π6

Approx. radians - 0.524

Last week Connor and his roommates ate 1 1/6 cartons of yogurt, and this week they ate 3 cartons. How much more yogurt did they eat this week compared to last week?

Answers

Answer:

dude I need like a picture or something to say

Express your answer to the 3rd sf 304.03 - 189.65

Answers

Answer:

114.4

Step-by-step explanation:

the answer is originally 114.38, but rounding it off makes it 114.4

Answer:

114.38 Is Your Answer

Translate the sentence into an equation. Three less than the product of 6 and a number equals 4. Use the variable b for the unknown number.​

Answers

Answer:

(6 x b) - 3 = 4

Step-by-step explanation:

or you can do 6b - 3 = 4

What is the solution given the expression
216^2/3

36
6
108
12

Answers

Answer:

36

Step-by-step explanation:

Noticing that 216 = 6^3 and using (x^a)^b = x^ab

216^2/3 = (6^3)^2/3 = 6^3 times 2/3 = 6^2 = 36

Mike has 25 toys. Lucy has 31 toys.
What number is equal to
Lucy's number of toys?

Answers

Answer:

31 - 25 = 6

Step-by-step explanation:

Have a good day! :)

There's a positive correlation between the amount of fertilizer a homeowner uses
and the height of the plants in her garden.
Which statement is true?
The correlation is most likely a causation.
The correlation is most likely a coincidence.
The correlation is most likely due to a lurking variable.

Answers

Answer:

The correlation is most likely a causation

Step-by-step explanation:

Causation

A change in one variable causes a change in another variable

Coincidence

The two variables are not related at all, but correlate by chance.

Lurking variable

A variable that is not measured in the study (i.e. it's a third variable that is neither the explanatory nor the response variable)

As fertilizer directly affects plant growth, then the correlation is most likely a causation

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