jinsuk Lee wrote:
The thing that I think is that a, a' proceed to increase 0.001.
so a, a' should be positive because it do convergence in positive values.
But My result value is negative value in case of some parts
Which would mean that in those cases there IS no positive solution! a and a' may come close for some positive value, but never get equal.
If "close" is enough, you may want rewrite your conditions to read like
| a2(....) - a | < 10^-3
etc.
and also write
0 < a < 1.
Maybe this helps but I am not sure what this would mean for your application.