# initial conditions in desolve

 1 In desolve, it is possible to specify (for a second order ODE) two different types of initial conditions i.e.: y(x_0) = y_0, y(x_1) = y_1 and y(x_0) = y_0, y'(x_0) = s_0. Is it also possible to specify initial conditions of the form y(x_0) = y_0, y'(x_1) = s_1? Thanks! asked Feb 21 '11 Chris 11 ● 3

## 1 Answer:

 1 I believe that only Dirichlet and Neumann boundary conditions are implemented (but would happy to be proven wrong). for a second-order equation, specify the initial x, y, and dy/dx, i.e. write [x_0, y(x_0), y'(x_0)] for a second-order boundary solution, specify initial and final x and y boundary conditions, i.e. write [x_0, y(x_0), x_1, y(x_1)]. So the first to boundary conditions you gave are ok. But the mixed boundary conditions don't work - you'll have to get the general solution and enforce the boundary conditions semi-manually. Here's a sage notebook with examples. posted Feb 21 '11 Simon 285 ● 2 ● 7 ● 18 http://www.physics.uwa.ed... Thanks a lot, Simon! Cheers, Chris Chris (Feb 22 '11)

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Asked: Feb 21 '11

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Last updated: Feb 21 '11

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