Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.soft-sys.math.maple > #864

Re: sqrt(1/sin(alpha))

Show all headers | View raw

In article <010320140625332981%edgar@math.ohio-state.edu.invalid>, G.
A. Edgar <edgar@math.ohio-state.edu.invalid> wrote:

> In article <5311ce00$0$3647$426a74cc@news.free.fr>, Jerome BENOIT
> <g6299304p@rezozer.net> wrote:
> 
> > Hello List,
> > 
> > so far I cannot figure out how to (simplify|convert) 
> > 
> > sqrt(1/sin(alpha));
> > 
> > into
> > 
> > 1/sqrt(sin(alpha));
> > 
> > 
> > Any idea ?
> > 
> > Thanks in advance,
> > Jerome
> 
> Maple does not do that "simplification" because it is wrong (for
> complex values).  If you like you can tell Maple more information:
> 
> u:=sqrt(1/sin(alpha));
> simplify(u) assuming sin(alpha)>0;

To see the incorrectness, do this:

u:=sqrt(1/sin(alpha));
v:=simplify(u) assuming sin(alpha)>0;
eval(u,alpha=-Pi/2);
eval(v,alpha=-Pi/2);

-- 
G. A. Edgar                              http://www.math.ohio-state.edu/~edgar/

Back to comp.soft-sys.math.maple | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

sqrt(1/sin(alpha)) Jerome BENOIT <g6299304p@rezozer.net> - 2014-03-01 13:09 +0100
  Re: sqrt(1/sin(alpha)) "G. A. Edgar" <edgar@math.ohio-state.edu.invalid> - 2014-03-01 06:25 -0700
    Re: sqrt(1/sin(alpha)) "G. A. Edgar" <edgar@math.ohio-state.edu.invalid> - 2014-03-01 06:34 -0700
      Re: sqrt(1/sin(alpha)) William Unruh <unruh@invalid.ca> - 2014-03-01 16:49 +0000
        Re: sqrt(1/sin(alpha)) fateman@gmail.com - 2014-03-10 07:57 -0700

csiph-web