Hi Viacheslav. Your examples and procedure, but without plugins (except your XYPlot plugin)
Best regards.
Alvaro.

Draghilev's method. Finding roots.sm (743.37 KiB) downloaded 713 time(s).

Wrote

As far as I can see there are no questions. As I said, everything is quite simple - we follow along the curve of n 1 space. Next, I will tell how to choose a start point, direction, and about the restrictions that follow from the method. I hope that the examples will be added.

From that 7 years old ... that works fine as downloaded,
but turns red as saved SS 6179, not doctored.
As offered in the attached, finding the max is acceptable.
The method suggested for the minima has not been tested.
As it looks: it fails ?

Mathhs NelderMead Himmelblau.sm (160.02 KiB) downloaded 648 time(s).
Maths Draghilev's method. Finding extremes. Himmelblau function version 0.2.sm (370.71 KiB) downloaded 675 time(s).

... that one.

Maths NelderMead Himmelblau.sm (160.02 KiB) downloaded 706 time(s).