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View Full Version : New angle makes trigonometry rational


igwt
09-18-2005, 10:23 PM
http://www.abc.net.au/reslib/200509/r58881_161538.jpg

Anyone recognize the sign?

ABC Link (http://www.abc.net.au/news/newsitems/200509/s1463334.htm)

Shannow
09-19-2005, 02:16 AM
The spread between two lines is a number between zero (representing parallel lines) and one (representing lines at right angles).

Sounds like Trig to me.

I'm working increasingly with graduate engineers from UNSW (btw, I went there, and spent a wonderful year annoying the ODdies)...it's very depressing to see the skills that they are leaving with.

Shannow
09-19-2005, 03:27 PM
Sounds really like trig to me now

http://web.maths.unsw.edu.au.nyud.net:8090/~norman/papers/Chapter1.pdf

freeman
09-19-2005, 03:42 PM
I'm no math whiz, but it just seems like a "recalibration" to me -- another way of doing the same thing.

Shannow
09-20-2005, 03:03 AM
freeman,
he uses pythagorus' theorem, but leaves out the square root (i.e. a calculation), and leaves the numbers as a squared.

Then instead of angles, uses the ratios of opposites (or adjacents) divided by the hypotenuse to define how far apart they are.

He's using trig, just using different terminology, and justifying it by simplicity.

Most engineers and mathematicians would work his way anyway, solving a formula at the end, rather than approximating (through a calculation) each step.

Anyway, the mason's used a compass to work out 30, 45, 60, and 90 degrees (they were so proud to teach us that in Grade 4), and as to

If the lines are close to being parallel, the angle is close to zero, while if the lines are
perpendicular, the angle turns out to be, after a highly non-trivial calculation going
back to Archimedes, a number with the approximate value 1. 570 796 326 . . . .


1.57076326x2 = 3.141592652...errm pi, back to the circular reference he started against.

freeman
09-20-2005, 04:41 AM
That's what I'm seeing too,Shannow.
...so what makes this "revolutionary"? :-?

Saturnino
09-20-2005, 10:49 AM
igwt wrote:
http://www.abc.net.au/reslib/200509/r58881_161538.jpg

Anyone recognize the sign?

ABC Link (http://www.abc.net.au/news/newsitems/200509/s1463334.htm)

OOOps !!! I do. In Brazil, this is the signal for the female genitalia. Don't do it around here !

igwt
09-21-2005, 12:20 AM
Saturnino wrote:

igwt wrote:
http://www.abc.net.au/reslib/200509/r58881_161538.jpg

Anyone recognize the sign?

ABC Link (http://www.abc.net.au/news/newsitems/200509/s1463334.htm)

OOOps !!! I do. In Brazil, this is the signal for the female genitalia. Don't do it around here !

Aside from the trig aspect the photo show a known signal.