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kompoz [17]
2 years ago
14

What is the exact value of cos (7pi/8)

Mathematics
1 answer:
Mrac [35]2 years ago
6 0

Answer:

The bottom one ....see below

Step-by-step explanation:

Using reference angle of pi/8   and half angle trig identity:

cos ( angle/2) = -sqrt  (1 + cos (angle) /2)

cos ( pi/4  / 2) = - sqrt (1+ cos ( pi/4)/2)

  <u> cos (pi/8)</u>      = -    sqrt (1 + sqrt (2) / 2)

                 = - sqrt (1 + sqrt 2) / sqrt 2     rationalize the denominator

                    = - sqrt ( sqrt 2 + 2) / 2

re arrange to

          - sqrt ( 2 + sqrt2)  / 2        the fourth answer  

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Write the following sets in set-builder notation: (a) The set of all humans whose first name is Tanya or Nelson.
Ulleksa [173]

Answer:

Step-by-step explanation:

Set is a well defined collection of objects .

We can express set in roaster form or set - builder form

<u>Roaster Form</u>

We express elements within curly brackets using commas between the elements .

<u>Set Builder Form</u>

In set builder form , all the elements of the set possess a common property which is not possess by elements outside the set .

We describe the elements of set using a symbol x which is followed by a colon . After colon , we write property possessed by the element and then enclosed the description within curly brackets .

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We need to write this one in set builder form .

Define set as follows : { x ∈ H : H is set of all the humans and x is either Tanya or Nelson }

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3 years ago
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Answer:

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4 0
3 years ago
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What is the altitude of a rhombus if its area is 10 square meters and the length on one side is 2.5 meters?
Elan Coil [88]
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You are in a bike race. When you get to the first checkpoint, you are 25 of the distance to the second checkpoint. When you get
Rom4ik [11]

Question:

You are in a bike race. When you get to the first checkpoint, you are 2/5 of the distance to the second checkpoint. When you get to the second check point, you are 1/4 of the distance to the finish. If the entire race is 40 miles, what is the distance between the start and the first check point?

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Step-by-step explanation:

Let distance between start to first checkpoint = x

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If start to checkpoint 2 = 1/4 of start to finish

Then,

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