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June 27th, 2017, 11:13 AM   #1
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Can Anyone find X on this paper?

Anyone find X on this paper?

https://docs.google.com/document/d/1...t?usp=drivesdk
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June 27th, 2017, 11:53 AM   #2
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The title says 'Using the cosine ratio to find the angle’s adjacent side', so my guess is that X is the adjacent.
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June 27th, 2017, 03:50 PM   #3
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Quote:
Originally Posted by 123qwerty View Post
The title says 'Using the cosine ratio to find the angle’s adjacent side', so my guess is that X is the adjacent.
So you can't figure it out either?

I can't see the benefit of calling adjacent/hypotenuse "a cosine" our giving a simple division a name at all

Also don't see how/why you use the length of the adjacent to calculate the length of the adjacent???????

Is the whole question bogus?????
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June 27th, 2017, 03:52 PM   #4
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Anyone else manage to workout the length of the adjacent by using the hypotenuse and one angle?
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June 27th, 2017, 04:10 PM   #5
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the expression to find it is circled in red on the sheet ...

the large X hi-lited in yellow is a multiplication symbol.

the small x in the chart and in the instructions represents the length of the adjacent side
Attached Images
File Type: jpg cosine_ratio.jpg (57.4 KB, 2 views)
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June 27th, 2017, 04:30 PM   #6
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So I don't use cosine at all but a calculator or lookup table that converts the angle - Cos 10

= 0.83907152907

So length of the adjacent = Hypotenuse x 0.83907152907
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June 27th, 2017, 04:55 PM   #7
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cos(10) = a/20

a = 20*cos(10)

which is approx. 19.7cm

*for the first one

Last edited by Antoniomathgini; June 27th, 2017 at 05:09 PM.
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June 27th, 2017, 06:46 PM   #8
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Quote:
Originally Posted by Gobsheite View Post
So you can't figure it out either?

I can't see the benefit of calling adjacent/hypotenuse "a cosine" our giving a simple division a name at all

Also don't see how/why you use the length of the adjacent to calculate the length of the adjacent???????

Is the whole question bogus?????
The benefit of using the cosine may not be immediately apparent when you first learn it, but as you learn more mathematics you'll find that it pops up fairly regularly in different applications.
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