Boundary value solutions



-----maxima-bounces at math.utexas.edu wrote: -----

>I have the equation of the elastic curve for a flat plate as
>follows

>w(x):=C1*sinh((2*u*x)/l)+C2*cosh((2*u*x)/l)+(q*l^3*x)/(8*u^2*D)+((-q)*l^2*
>x^2)/(8*u^2*D)+((-q)*l^4)/(16*u^4*D)
>with boundary values w=0 @ x=0 and x=l.
>How do I formulate the solution yielding C1 and C2? q, u, D
>are all know values.

Try this:

(%i5)
 w(x):=C1*sinh((2*u*x)/l)+C2*cosh((2*u*x)/l)+(q*l^3*x)/(8*u^2*D)+((-q)*l^2*x^2)/(8*u^2*D)

 +((-q)*l^4)/(16*u^4*D)$

(%i7) algsys([w(0),w(l)],[C1,C2]);
(%o7)
[[C1=-(l^4*q*cosh(2*u)-l^4*q)/(16*u^4*sinh(2*u)*D),C2=(l^4*q)/(16*u^4*D)]]

(%i8) subst(%,w(x));
(%o8) <...stuff deleted...>

Barton