Whakaoti i te 2x^2+18=0?

$$2 x ^ { 2 } + 18 = 0 ?$$

Whakaoti mō x (complex solution)

$$x=-3i$$

$$x=3i$$

Ngā Upane mā te Kimi Pūtakerua

Tangohia te 18 mai i ngā taha e rua. Ko te tau i tango i te kore ka hua ko tōna korenga.

$$2x^{2}=-18$$

Whakawehea ngā taha e rua ki te 2.

$$x^{2}=\frac{-18}{2}$$

Whakawehea te -18 ki te 2, kia riro ko -9.

$$x^{2}=-9$$

Kua oti te whārite te whakatau.

$$x=3i x=-3i$$

Ngā Upane e Whakamahi ana i te Tikanga Tātai Pūrua

Ko ngā tikanga tātai pūrua pēnei i tēnei nā, me te kīanga tau x^{2} engari kāore he kīanga tau x, ka taea tonu te whakaoti mā te whakamahi i te tikanga tātai pūrua, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, ina tuhia ki te tānga ngahuru: ax^{2}+bx+c=0.

$$2x^{2}+18=0$$

Kei te āhua arowhānui tēnei whārite: ax^{2}+bx+c=0. Me whakakapi 2 mō a, 0 mō b, me 18 mō c i te tikanga tātai pūrua, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\times 2\times 18}}{2\times 2}$$

Pūrua 0.

$$x=\frac{0±\sqrt{-4\times 2\times 18}}{2\times 2}$$

Whakareatia -4 ki te 2.

$$x=\frac{0±\sqrt{-8\times 18}}{2\times 2}$$

Whakareatia -8 ki te 18.

$$x=\frac{0±\sqrt{-144}}{2\times 2}$$

Tuhia te pūtakerua o te -144.

$$x=\frac{0±12i}{2\times 2}$$

Whakareatia 2 ki te 2.

$$x=\frac{0±12i}{4}$$

Nā, me whakaoti te whārite x=\frac{0±12i}{4} ina he tāpiri te ±.

$$x=3i$$

Nā, me whakaoti te whārite x=\frac{0±12i}{4} ina he tango te ±.

$$x=-3i$$

Kua oti te whārite te whakatau.

$$x=3i x=-3i$$