On Thu, Jun 07, 2007 at 10:36:33PM +0100, Gregory Hughes wrote:
> Hello all,
> I have a simple(ish) question about solve. I have an equation,
> called "test" I want to solve "test" for the value "fl". I know the
> values "r" and "c." Likewise, I actually also know the proper value
> for "fl", but I can't get Maxima to give it to me.
>
> /*-------------*/
> /* My test equation */
> test:6096*tan((2*atan(c/(2*fl)))/r) / (tan(((1/60)*(%pi/180))));
> /* solve for fl ... */
> solve(test=6096,fl);
See my previous email about solve's hesitance to delve into this
equation. To do it manually you can do the following, but I haven't
thought about the math here, only getting maxima to do the naive
algebra.
(%i8) pickapart(test,3);
c
2 atan(----)
2 fl
(%t8) ------------
r
6096 tan(%t8)
(%o8) -------------
%pi
tan(-----)
10800
(%i9) solve(%o8=6096,'%t8);
`solve' is using arc-trig functions to get a solution.
Some solutions will be lost.
%pi
(%o9) [%t8 = -----]
10800
(%i10) ev(%);
c
2 atan(----)
2 fl %pi
(%o10) [------------ = -----]
r 10800
(%i11) solve(first(%),fl);
c
(%o11) [fl = ------------]
%pi r
2 tan(-----)
21600
--
Daniel Lakeland
dlakelan at street-artists.org
http://www.street-artists.org/~dlakelan