My Math Forum Can Anyone find X on this paper?

 Trigonometry Trigonometry Math Forum

 June 27th, 2017, 11:13 AM #1 Newbie   Joined: Jun 2017 From: Loughborough Posts: 5 Thanks: 0 Can Anyone find X on this paper? Anyone find X on this paper? https://docs.google.com/document/d/1...t?usp=drivesdk
 June 27th, 2017, 11:53 AM #2 Senior Member   Joined: Dec 2012 From: Hong Kong Posts: 853 Thanks: 311 Math Focus: Stochastic processes, statistical inference, data mining, computational linguistics The title says 'Using the cosine ratio to find the angle’s adjacent side', so my guess is that X is the adjacent.
June 27th, 2017, 03:50 PM   #3
Newbie

Joined: Jun 2017
From: Loughborough

Posts: 5
Thanks: 0

Quote:
 Originally Posted by 123qwerty 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?????

 June 27th, 2017, 03:52 PM #4 Newbie   Joined: Jun 2017 From: Loughborough Posts: 5 Thanks: 0 Anyone else manage to workout the length of the adjacent by using the hypotenuse and one angle?
June 27th, 2017, 04:10 PM   #5
Math Team

Joined: Jul 2011
From: Texas

Posts: 3,002
Thanks: 1588

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
 cosine_ratio.jpg (57.4 KB, 2 views)

 June 27th, 2017, 04:30 PM #6 Newbie   Joined: Jun 2017 From: Loughborough Posts: 5 Thanks: 0 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
 June 27th, 2017, 04:55 PM #7 Member   Joined: Apr 2017 From: Canada Posts: 32 Thanks: 2 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.
June 27th, 2017, 06:46 PM   #8
Senior Member

Joined: Dec 2012
From: Hong Kong

Posts: 853
Thanks: 311

Math Focus: Stochastic processes, statistical inference, data mining, computational linguistics
Quote:
 Originally Posted by Gobsheite 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.

 Tags find, paper

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post Yvan Advanced Statistics 3 October 16th, 2013 10:53 AM Crouch Number Theory 14 May 24th, 2012 12:05 AM Deb_D Advanced Statistics 3 November 23rd, 2010 09:07 AM plsm Applied Math 0 June 10th, 2009 06:02 PM bigli Real Analysis 3 May 22nd, 2007 10:00 AM

 Contact - Home - Forums - Cryptocurrency Forum - Top