quadraticformula x^2-5x-1=0

解

x^{2} - 5 x - 1 = 0

x = \frac{5 + 29}{2}, x = \frac{5 - 29}{2}

十進法表記

x = 5.19258 \dots, x = - 0.19258 \dots

解答ステップ

x^{2} - 5 x - 1 = 0

解くとthe二次式

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

(- 5)^{2} - 4 \cdot 1 \cdot (- 1) = 29

x_{1, 2} = \frac{- ( - 5 ) \pm 29}{2 \cdot 1}

解を分離する

x_{1} = \frac{- ( - 5 ) + 29}{2 \cdot 1}, x_{2} = \frac{- ( - 5 ) - 29}{2 \cdot 1}

x = \frac{- ( - 5 ) + 29}{2 \cdot 1} : \frac{5 + 29}{2}

x = \frac{- ( - 5 ) - 29}{2 \cdot 1} : \frac{5 - 29}{2}

二次equationの解:

x = \frac{5 + 29}{2}, x = \frac{5 - 29}{2}