Mataupu
Fa'atusa fa'afa'afa ose fa'atusatusaga fa'a-matematika, lea e foliga fa'apitoa e fa'apea:
ax2 + bx + c = 0
Ole fa'asologa lona lua lea ole polynomial ma 3 coefficients:
- a – matua (muamua) coefficient, e le tatau ona tutusa ma le 0;
- b – averesi (lua) coefficient;
- c o se elemene saoloto.
Ole fofo ile fa'atusa fa'afa'afa ole su'e numera lua (ona a'a) – x1 ma x2.
Fuafua mo le fuafuaina o a'a
Ina ia maua a'a o se fa'atusa fa'atusa, e fa'aaoga le fua fa'atatau:
O le faaupuga i totonu o le a'a sikuea e ta'ua faʻailoga tagata ma ua faailogaina i le mataitusi D (po'o le Δ):
D = b2 - 4ac
I lenei auala, O le fua mo le fuafuaina o aʻa e mafai ona faʻatusalia i auala eseese:
1 D > 0, o le fa'atusa e 2 a'a:
2 D = 0, o le fa'atusa e na'o le tasi le a'a:
3 D < 0, вещественных корней нет, но есть комплексные:
Fofo o faiga fa'atusa
Faataitaiga 1
3x2 + 5x +2 = 0
Filifiliga:
a = 3, b = 5, c = 2
x1 = (-5 + 1) / 6 = -4/6 = -2/3
x2 = (-5 – 1) / 6 = -6/6 = -1
Faataitaiga 2
3x2 - 6x +3 = 0
Filifiliga:
a = 3, b = -6, c = 3
x1 = x2 = 1
Faataitaiga 3
x2 + 2x +5 = 0
Filifiliga:
a = 1, b = 2, c = 5
I lenei tulaga, e leai ni aʻa moni, ma o le fofo o numera lavelave:
x1 = -1 + 2i
x2 = -1 – 2i
Kalafi o se galuega fa'afa'afa
Ole kalafi ole galuega fa'afa'afa ole o se faataoto.
f(x) = ax2 + bx + i
- O a'a o se fa'atusatusaga fa'afa'afa'afa'afa'a'ai o vaega ia o le va'aiga o le parabola ma le axis abscissa. (X).
- Afai e na'o le tasi le a'a, o le parabola e pa'i i le axis i le tasi itu e aunoa ma le sopoia.
- I le leai o ni aʻa moni (le iai o mea faʻalavelave), o se kalafi ma se axis X e le pa'i atu.