zhu laojianke wrote:
I use the nth_root(), but the graph what I have got is not like you've pasted there...
This is possibly because you used a different numeric algorithm. Right click on the word odesolve and look what you have chosen. Usually "Adams/BDF" or Adaptive are a good choice. I guess you have chosen "Fixed".
BTW, here is another way to force real values for any root. It depends on the underlying problem if any of these workarounds make sense!
You can also try to increase accuracy by setting TOL to a value lower than the default 10^-3.
