Find the angle between two tangents by iterating en2



On Fri, Sep 3, 2010 at 10:22 AM, William Porter
<wmporter.omegapar at comcast.net> wrote:

> (%i8) [(%phi[1]*d*(-2)),(d+((%phi[1])^(2)*d*(-1)))]$
> ????????? [(%phi[2]*d*(-2)),(d+((%phi[2])^(2)*d*(-1)))]$
>
> ((%pi*1/2)+(atan((((%phi[1]+(%phi[2]*(-1))))^((-1))*(1+(%phi[2]*%phi[1]))))*(-1)));
> (%i9) %,numer;

%o8 is the expression you want to evaluate to 0.1674317785, right?
If so, at this point you want something like:

 find_root(%o8 - 0.1674317785, en2, 10, 80);

Maybe I'm mistaken about which expression is supposed
to evaluate to 0.1674317785, I wouldn't be surprised.
If so, just substitute that other expression for %o8 above.

You don't need anything else beyond the call to find_root.
In particular you don't need to construct a loop of any kind.

HTH

Robert Dodier