Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.

Topic: asin2?
Replies: 26   Last Post: Dec 20, 2011 2:24 PM

 Messages: [ Previous | Next ]
 Virgil Hancher Posts: 3,758 Registered: 12/6/04
Re: asin2?
Posted: Aug 15, 2000 12:33 AM

In article <5s1m5.866\$9N1.14757@vixen.cso.uiuc.edu>,
prussing@aae.uiuc.edu (John Prussing) wrote:

> So, if you think a function asin2 can be defined, let's hear from you.
> As a test case, I offer sin(theta) = 1/sqrt(2).

Assuming that true conditionals return 1 and false ones return 0,
and that r = sqrt(x^2+y^2) > 0, then

theta = (-1)^(x<0)*arcsin(y/r) + (x<0)*pi

gives a correct angle for each point (x,y), except possibly (0,0) for
which no angle is defined.

The range of theta in radians is -pi/2 <= theta < 3*pi/2, rather than
the or common 0 to 2*pi or -pi to pi. That could be fixed with a little

Date Subject Author
8/14/00 John Prussing
8/15/00 Virgil Hancher
8/15/00 Doug Magnoli
8/15/00 John Prussing
8/16/00 Virgil Hancher
8/16/00 David W. Cantrell
8/16/00 Gordon Sande
8/16/00 David W. Cantrell
8/16/00 John Prussing
8/16/00 David W. Cantrell
8/17/00 John Prussing
8/17/00 David W. Cantrell
8/17/00 Virgil Hancher
8/17/00 John Prussing
8/15/00 Lynn Killingbeck
8/15/00 John Prussing
8/15/00 Virgil Hancher
8/15/00 Hermann Kremer
8/15/00 John Prussing
8/16/00 Hermann Kremer
8/16/00 John Prussing
8/15/00 David W. Cantrell
8/15/00 John Prussing
12/20/11 Aaron Bergquist
8/17/00 Lawrence Kirby
8/17/00 John Prussing
8/17/00 David W. Cantrell