NDSolve

*To*: mathgroup at smc.vnet.net*Subject*: [mg21471] NDSolve*From*: Klaus Wallmann <kwallmann at geomar.de>*Date*: Tue, 11 Jan 2000 04:17:50 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Using MATHEMATICA Version 4.0 on a Pentium III PC with Windows NT Version 4, I tried to solve the following ordinary homogeneous non-linear second order differential equation with variable coefficients: y''[t] + p[t] y'[t] + q[t] y[t]/(y[t]+K) = 0 with boundary conditions y[10] = 29 y'[6000] = 0 and K = 1 p[t] = ((-1.15301 (-3 + ln[(0.769 + 0.102 exp(-0.036 t))^(2)]) + 0.2307 exp(+0.036 t) (-1 + ln[(0.769 + 0.102 exp(-0.036 t))^(2)])^(2))/(314 (0.871 + 0.769 (-1 + exp(+0.036 t) (-1 + ln[(0.769 + 0.102 exp(-0.036 t))^(2)])) q[t] = -[0.00203318 (0.231 - 0.102 exp(-0.036 t)) (0.102 (0.697676 - exp(-0.036 t))+ 0.008316 (93.2 + t))^(-1.142) (1 - ln[(0.769 + 0.102 exp(-0.036 t))^(2)])]/(0.769 + 0.102 exp (-0.036 t)) I tried NDSolve to solve this equation but I did not succeed. Is it possible to solve this equation or similar differential equations using the numerical procedures implemented in MATHEMATICA? Sincerely Klaus Wallmann