Okuqukethwe
Isibalo sequadratic isibalo sezibalo, ngokuvamile esibukeka kanje:
ax2 + bx + c = 0
Leli i-oda lesibili le-polynomial elinama-coefficient angu-3:
- a - i-coefficient ephezulu (yokuqala), akufanele ilingane no-0;
- b - isilinganiso (yesibili) coefficient;
- c iyisici samahhala.
Isixazululo se-quadratic equation ukuthola izinombolo ezimbili (izimpande zayo) - x1 kanye x2.
Ifomula yokubala izimpande
Ukuthola izimpande ze-quadratic equation, ifomula isetshenziswa:
Isisho esingaphakathi kwempande yesikwele sibizwa ukubandlulula futhi imakwe ngohlamvu D (noma Δ):
D = b2 - 4ac
Ngale ndlela, Ifomula yokubala izimpande ingamelwa ngezindlela ezahlukene:
1 Uma D > 0, isibalo sinezimpande ezi-2:
2 Uma D = 0, isibalo sinempande eyodwa kuphela:
3 Uma D < 0, вещественных корней нет, но есть комплексные:
Izixazululo zezibalo ze-quadratic
Isibonelo se-1
3x2 5 +x + 2 = 0
Isinqumo:
a = 3, b = 5, c = 2
x1 = (-5 + 1) / 6 = -4/6 = -2/3
x2 = (-5 – 1) / 6 = -6/6 = -1
Isibonelo se-2
3x2 - 6x + 3 = 0
Isinqumo:
a = 3, b = -6, c = 3
x1 = x2 = 1
Isibonelo se-3
x2 2 +x + 5 = 0
Isinqumo:
a = 1, b = 2, c = 5
Kulokhu, azikho izimpande zangempela, futhi isisombululo izinombolo eziyinkimbinkimbi:
x1 = -1 + 2i
x2 = -1 – 2i
Igrafu yomsebenzi we-quadratic
Igrafu yomsebenzi we-quadratic ngu umfanekiso.
f(x) = ax2 + b x + c
- Izimpande ze-quadratic equation amaphuzu okuhlangana kwe-parabola ne-abscissa axis (X).
- Uma kukhona impande eyodwa kuphela, i-parabola ithinta i-eksisi ngesikhathi esisodwa ngaphandle kokuyiwela.
- Uma kungekho izimpande zangempela (ukuba khona kweziyinkimbinkimbi), igrafu ene-eksisi X ayithinti.