Whakaoti i te 4^2-4(k-1)(1)<0

$$4 ^ { 2 } - 4 ( k - 1 ) ( 1 ) < 0$$

Whakaoti mō k

$$k>5$$

Ngā Upane Otinga

Tātaihia te 4 mā te pū o 2, kia riro ko 16.

$$16-4\left(k-1\right)\times 1<0$$

Whakareatia te 4 ki te 1, ka 4.

$$16-4\left(k-1\right)<0$$

Whakamahia te āhuatanga tohatoha hei whakarea te -4 ki te k-1.

$$16-4k+4<0$$

Tāpirihia te 16 ki te 4, ka 20.

$$20-4k<0$$

Tangohia te 20 mai i ngā taha e rua. Ko te tau i tango i te kore ka hua ko tōna korenga.

$$-4k<-20$$

Whakawehea ngā taha e rua ki te -4. I te mea he tōraro a -4, ka huri te ahunga koreōrite.

$$k>\frac{-20}{-4}$$

Whakawehea te -20 ki te -4, kia riro ko 5.

$$k>5$$