Whakaoti i te x^2-2x-2=0

$$x ^ { 2 } - 2 x - 2 = 0$$

Whakaoti mō x

$$x=\sqrt{3}+1\approx 2.732050808$$

$$x=1-\sqrt{3}\approx -0.732050808$$

Ngā Upane e Whakamahi ana i te Tikanga Tātai Pūrua

Ko ngā whārite katoa o te āhua ax^{2}+bx+c=0 ka taea te whakaoti mā te whakamahi i te tikanga tātai pūrua: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. E rua ngā otinga ka puta i te tikanga tātai pūrua, ko tētahi ina he tāpiri a ±, ā, ko tētahi ina he tango.

$$x^{2}-2x-2=0$$

Kei te āhua arowhānui tēnei whārite: ax^{2}+bx+c=0. Me whakakapi 1 mō a, -2 mō b, me -2 mō c i te tikanga tātai pūrua, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{-\left(-2\right)±\sqrt{\left(-2\right)^{2}-4\left(-2\right)}}{2}$$

Pūrua -2.

$$x=\frac{-\left(-2\right)±\sqrt{4-4\left(-2\right)}}{2}$$

Whakareatia -4 ki te -2.

$$x=\frac{-\left(-2\right)±\sqrt{4+8}}{2}$$

Tāpiri 4 ki te 8.

$$x=\frac{-\left(-2\right)±\sqrt{12}}{2}$$

Tuhia te pūtakerua o te 12.

$$x=\frac{-\left(-2\right)±2\sqrt{3}}{2}$$

Ko te tauaro o -2 ko 2.

$$x=\frac{2±2\sqrt{3}}{2}$$

Nā, me whakaoti te whārite x=\frac{2±2\sqrt{3}}{2} ina he tāpiri te ±. Tāpiri 2 ki te 2\sqrt{3}.

$$x=\frac{2\sqrt{3}+2}{2}$$

Whakawehe 2+2\sqrt{3} ki te 2.

$$x=\sqrt{3}+1$$

Nā, me whakaoti te whārite x=\frac{2±2\sqrt{3}}{2} ina he tango te ±. Tango 2\sqrt{3} mai i 2.

$$x=\frac{2-2\sqrt{3}}{2}$$

Whakawehe 2-2\sqrt{3} ki te 2.

$$x=1-\sqrt{3}$$

Kua oti te whārite te whakatau.

$$x=\sqrt{3}+1 x=1-\sqrt{3}$$

Ngā Upane mō te Whakaoti i te Pūrua

Ko ngā whārite pūrua pēnei i tēnei nā ka taea te whakaoti mā te whakaoti i te pūrua. Hei whakaoti i te pūrua, ko te whārite me mātua tuhi ki te āhua x^{2}+bx=c.

$$x^{2}-2x-2=0$$

Me tāpiri 2 ki ngā taha e rua o te whārite.

$$x^{2}-2x-2-\left(-2\right)=-\left(-2\right)$$

Mā te tango i te -2 i a ia ake anō ka toe ko te 0.

$$x^{2}-2x=-\left(-2\right)$$

Tango -2 mai i 0.

$$x^{2}-2x=2$$

Whakawehea te -2, te tau whakarea o te kīanga tau x, ki te 2 kia riro ai te -1. Nā, tāpiria te pūrua o te -1 ki ngā taha e rua o te whārite. Mā konei e pūrua tika tonu ai te taha mauī o te whārite.

$$x^{2}-2x+1=2+1$$

Tāpiri 2 ki te 1.

$$x^{2}-2x+1=3$$

Tauwehea x^{2}-2x+1. Ko te tikanga pūnoa, ina ko x^{2}+bx+c he pūrua tika pūrua tika pū, ka taea taua mea te tauwehea i ngā wā katoa hei \left(x+\frac{b}{2}\right)^{2}.

$$\left(x-1\right)^{2}=3$$

Tuhia te pūtakerua o ngā taha e rua o te whārite.

$$\sqrt{\left(x-1\right)^{2}}=\sqrt{3}$$

Whakarūnātia.

$$x-1=\sqrt{3} x-1=-\sqrt{3}$$

Me tāpiri 1 ki ngā taha e rua o te whārite.

$$x=\sqrt{3}+1 x=1-\sqrt{3}$$