El dom, 12-03-2006 a las 21:06 -0800, Nguyen Huong escribi??:
> Hi all,
>
> Now I try to solve three equations in Maxima:
>
> dy(x)/d(x) = x and y(2) = 0 and y(x) = 0.
>
> If I do it manually, I do it as follows:
>
> dy(x)/dx = x --> y = (x^2)/2 + C
> y(2) = 0 --> C = -2
> y(x) = 0--> (x^2)/2 - 2 = 0 --> x = 2 or x = -2.
>
> However, I do not know how to deal with these three equations in
> Maxima to find the value of x.
>
> When I try to calculate the integration of dy(x)/dx = x in Maxima
>
> (%i1) integrate(x,x)
> (%o1) (x^2)/2
>
> The result returned by Maxima does not include the constant C, so I do
> not know how to continue in Maxima to find the results.
>
> If anyone knows, please help me. I appreciate for that. Thanks.
>
> Nguyen,
Hi Nguyen,
describe(ode2), describe(ic1) and describe(ic2) give you information
about how to handle differential equations in Maxima:
/************ begin Maxima session **********************/
(%i1) eq: 'diff(y,x)=x; /* note the quote ' here */
dy
(%o1) -- = x
dx
(%i2) ode2(eq,y,x);
2
x
(%o2) y = -- + %c
2
(%i3) ic1(%,x=2,y=0);
2
x - 4
(%o3) y = ------
2
/************ begin Maxima session **********************/
Hope this helps.
--
Mario Rodriguez Riotorto
www.biomates.net