how do i use BVP4C for these kind of coupled odes?

The equations are coupled

C1 p(x) + C2 dp(x)/dx + C3 u(x) + C4 du(x)/dx = 0

C5 p(x) + C6 dp(x)/dx + C7 u(x) + C8 du(x)/dx = 0

I want to give two boundary conditions, one at each end. (thus cannot use ode45).

I have seen how bvp4c works with higher order odes with boundary value problems. the difficulty here is that the first order coupled equations both contain the first derivatives of each terms. Any help is appreciated. Thanks

Answer 1

[Torsten]

Can you solve

C2*a + C4*b = -C1*p(x) - C3*u(x)
C6*a + C8*b = -C5*p(x) - C7*u(x)

for a and b ?

If this is the case, then

a = dp(x)/dx , b = du(x)/dx.

Best wishes

Torsten.