# Question:dsolve Error, an excessive amount of work (greater than mxstep) was done

## Question:dsolve Error, an excessive amount of work (greater than mxstep) was done

Hi!

I have been trying to solve the following system of equations:

ODEs:=diff(f[0, 0](x), x)+2.*f[0, 0](x)/x^5+.5000000000*f[0, 0](x)/x+0.1500000000e-1*f[0, 1](x)/sqrt(x) = -15.58845727*sin(.5773502693*x)/x^2+140.2961154*sin(.5773502693*x)/x^4-81.*cos(.5773502693*x)/x^3, diff(f[0, 1](x), x)+2.*f[0, 1](x)/x^5+.5000000000*f[0, 1](x)/x-0.6666666667e-2*f[0, 0](x)/sqrt(x) = -1039.230485*sin(.5773502693*x)/x^(5/2)+600.0000000*cos(.5773502693*x)/x^(3/2)-346.4101616*sin(.5773502693*x)/x^(9/2)+2078.460970*sin(.5773502693*x)/x^(13/2)-1200.000000*cos(.5773502693*x)/x^(11/2), f[0, 0](.1) = 1.503498543, f[0, 1](.1) = -1.053038610

Using dsolve I cant get it to work. I have tried both dverk78 and lsode methods, with default options. For example:

Sollsode := dsolve({ODEs}, numeric, method = lsode)

Gives me the follwing error, if I try to estimate the solution anywhere past the initial point of 0.1: Error, (in Sollsode) an excessive amount of work (greater than mxstep) was done

I have also attempted to solve it with dverk78, thinking perhaps the improved accuracy of the method will help.

Soldverk := dsolve({ODEs}, numeric, method = dverk78)

However I will get the following error message then: Error, (in Soldverk) cannot evaluate the solution past .10000000, step size < hmin, problem may be singular or error tolerance may be too small

Any ideas on how to proceed? Thanks so much!

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