Thanks for your reply
It seems that I cannot use find_root because it is not continuos
over 0.
On Jun 7, 2007, at 11:06 PM, Daniel Lakeland wrote:
> 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
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