tirotiro
Whārite tapawhā he whārite pāngarau, e pēnei ana te āhua:
ax2 + bx + c = 0
Koinei te raupapa tuarua o te polynomial me te 3 whakarea:
- a – whakarea matua (tuatahi), kaua e rite ki te 0;
- b – tauwaenga (tuarua) whakarea;
- c he huānga kore utu.
Ko te otinga o te whārite tapawhā ko te kimi i ngā tau e rua (ōna pūtake) – x1 me te x2.
Te tātai mō te tātai i ngā pakiaka
Hei kimi i nga putake o te wharite tapawha, ka whakamahia te tauira:
Ko te kupu i roto i te pakiaka tapawha ka kiia whakahāwea a kua tohua ki te reta D (Δ ranei):
D = b2 - 4ac
I tenei ara, Ko te tauira mo te tatau i nga pakiaka ka taea te whakaatu i nga huarahi rereke:
1 D > 0, e 2 ngā pūtake o te whārite:
2 D = 0, kotahi anake te pūtake o te whārite:
3 D < 0, вещественных корней нет, но есть комплексные:
Nga otinga o nga whārite tapawhā
tauira 1
3x2 + 5x +2 = 0
Te whakatau:
a = 3, b = 5, c = 2
x1 = (-5 + 1) / 6 = -4/6 = -2/3
x2 = (-5 – 1) / 6 = -6/6 = -1
tauira 2
3x2 - 6x +3 = 0
Te whakatau:
a = 3, b = -6, c = 3
x1 = x2 = 1
tauira 3
x2 + 2x +5 = 0
Te whakatau:
a = 1, b = 2, c = 5
I tenei keehi, karekau he tino putake, he tau uaua te otinga:
x1 = -1 + 2i
x2 = -1 – 2i
Kauwhata o te mahi tapawhā
Ko te kauwhata o te mahi tapawhā ko he kupu whakarite.
f(x) = ax2 + b x + c
- Ko nga putake o te wharite tapawha ko nga pito o te mokowhititanga o te parapara me te tuaka abscissa (X).
- Mena kotahi anake te pakiaka, ka pa te parapara ki te tuaka i tetahi waahi kaore e whakawhiti.
- Ki te kore he tino putake (te aroaro o nga mea uaua), he kauwhata whai tuaka X e kore e pa.