I'm a newbie.I am trying to solve a differential equation symbolically.But I'm having  a\some problem.

First 3 lines works fine....but 4th line gives no output...

Secondly How I'm supposed to simplify the output of 3rd line

1.>ode := P*(diff(y(x), x, x))+diff( K(x)*(diff(y(x), x, x)), x, x ) = 0

2.>ics := y(0) = 0, y(L) = 0, ((D@@2)(y))(0) = 0, ((D@@2)(y))(L) = 0

3.>dsolve(ode, y(x))

3rd lines output--y(x) = _C2*x+_C1+Int(DESol({diff(_Y(x), x, x)+2*(diff(K(x), x))*(diff(_Y(x), x))/K(x)+(P+diff(K(x), x, x))*_Y(x)/K(x)}, {_Y(x)}), [x, x]) 

4.>dsolve({ics,ode},y(x))

5.>

4th lines gives no output.After hitting "Enter",I get a new line in my Worksheet(line 5).Why..can anyone explain please?

I am a newbie. I m having some problems in solving generalised eigenvalue problem for symbolic matrices. Help me to discover the problems with this code.

Here is my code:-

>with(LinearAlgebra):

> M := Matrix(2, 2, [4*(I*E/L^3), 6*(I*E/L^3), 6*(I*E/L^3), 24*(I*E/L^3)])

> G :=Matrix(2,2,[2/(15)(-1/(L)),1/(10)(-1/(L)),1/(10)(-1/(L)),12/(5)(-1/(L))])

> Eigenvalues(M, G, output = 'Vector[row]')

Error:-

Error, (in LinearAlgebra:-Eigenvalues) invalid input: LinearAlgebra:-Eigenvalues expects its 2nd argument, C, to be of type Matrix(square) but received G