Help in Mathematica code for solutions expansion of differential equations

[jadyliber]

I need to NDsolve four differential equations.
But I find my code does not work. Who can give me some suggestions? Thanks!

 

[jackmell]

I need to NDsolve four differential equations.
But I find my code does not work. Who can give me some suggestions? Thanks!
the equations:

Move it to the Mathematica forum, get rid of all that messy code, scrap all but one of them, write it neatly, and wait for help.

 

[jadyliber]

I am sorry for it.
by the way, is there a Mathematica forum? thanks for advices

 

[Bill Simpson]

is there a Mathematica forum?

Here
https://www.physicsforums.com/forumdisplay.php?f=189
or here
http://forums.wolfram.com/student-support/discussions/4/

As suggested, simplify your notebook as much as possible and describe exactly what the problem is with the result you are getting. Look at other postings there to see how people include a small notebook with their question, demonstrate their problem and ask their questions. Look at the posts that get answers for good examples.

The posts that do not get good answers say "Something is wrong using NDSolve. what do I do?"

 

[jackmell]

Also, if you need to cut and paste your code, first convert it to Raw input form: highlight it, then select Cell/Convert To/Raw Input form. Then cut and paste it like I do below. Then wrap it in the code blocks:

mysol = NDSolve[{Derivative[1][y][x] + 
      (2*x + 1)*y[x] == 0, y[0] == 1}, y, {x, 0, 5}]
myPlot = Plot[y[x] /. mysol, {x, 0, 5}]

 

[jadyliber]

Thanks again to bill & jack