quadraticformula x^2-4x+5=0

解

x^{2} - 4 x + 5 = 0

x = 2 + i, x = 2 - i

解答ステップ

x^{2} - 4 x + 5 = 0

解くとthe二次式

x_{1, 2} = \frac{- ( - 4 ) \pm ( - 4 ) ^{2} - 4 \cdot 1 \cdot 5}{2 \cdot 1}

簡素化

(- 4)^{2} - 4 \cdot 1 \cdot 5 : 2 i

x_{1, 2} = \frac{- ( - 4 ) \pm 2 i}{2 \cdot 1}

解を分離する

x_{1} = \frac{- ( - 4 ) + 2 i}{2 \cdot 1}, x_{2} = \frac{- ( - 4 ) - 2 i}{2 \cdot 1}

x = \frac{- ( - 4 ) + 2 i}{2 \cdot 1} : 2 + i

x = \frac{- ( - 4 ) - 2 i}{2 \cdot 1} : 2 - i

二次equationの解:

x = 2 + i, x = 2 - i