Izoh: Olingan yoyilmada D(y)(0) noldagi hosilani bildiradi: y'(0). Xususiy yechimni topish uchun boshlang’ich shartlarni berish qoldi:
> y(0):=1: D(y)(0):=0:f;
2. Koshi masalasining taqribiy yechimini 5-tartibli aniqlikgacha darajali qator ko’rinishida va aniq yechimini toping: , , , . Bitta rasmda aniq va taqribiy yechimlar grafigini chizing.
> restart; Order:=6: > de:=diff(y(x),x$3)-diff(y(x),x)=3*(2-x^2)*sin(x); de:= > cond:=y(0)=1, D(y)(0)=1, (D@@2)(y)(0)=1; cond:=y(0)=1, D(y)(0)=1, D(2)(y)(0)=1
> dsolve({de,cond},y(x)); y(x)=
> y1:=rhs(%): > dsolve({de,cond},y(x), series); y(x)=
Izoh: qator ko’rinishidagi differensial tenglamaning yechimi series turiga tegishli, shuning uchun bunday yechimdan keyinchalik foydalanish uchun uni convert buyrug’i yordamida albatta ko’phad ko’rinishiga keltirish kerak.
> convert(%,polynom): y2:=rhs(%): > p1:=plot(y1,x=-3..3,thickness=2,color=black): > p2:=plot(y2,x=-3..3, linestyle=3,thickness=2,color=blue): > with(plots): display(p1,p2);
Rasmda ko’rinib turibdiki, darajali qatorning aniq yechimiga yaqinlashishi taxminan - 1<x<1 oraliqda amalga oshadi.
Differensial tenglamalarni sonli yechish Differensial tenglamaning sonli yechimini topish uchun dsolve buyrug’ida type=numeric( yoki oddiy numeric) parametrni ko’rsatish kerak bo’ladi. Bu holda differensial tenglamani yechish buyrug’i quyidagicha ko’rinishda bo’ladi: dsolve(eq, vars, type=numeric, options), bu yerda eq – tenglama, vars – noma’lum funksiyalar ro’yxati, options – differensial tenglamani sonli integrallash metodlarini ko’rsatuvchi parametrlar.
Maple muhitida quyidagilar metodlar ishlatiladi: method=rkf45 – 4-5 tartibli Runge-Kutta-Felberg metodi; method=dverk78 – 7-8 tartibli Runge-Kutta metodi; mtthod=classical – 5- tartibli Runge-Kutta klassik metodi; method=gear vamethod=mgear – bir qadamli va ko’pqadamli Gira metodlari.
