摘要:
http://www.sagemath.org/doc/reference/sage/plot/plot_field.html &plot_vector_field 阅读全文
摘要:
http://maxima.sourceforge.net/docs/manual/de/maxima_66.html#SEC354 Examples: To show the direction field of the differential equationy' = exp(-x) + yand the solution that goes through(2, -0.1):(... 阅读全文