p^2-2p-8=0

解

p^{2} - 2 p - 8 = 0

p = 4, p = - 2

解答ステップ

p^{2} - 2 p - 8 = 0

解くとthe二次式

p_{1, 2} = \frac{- ( - 2 ) \pm ( - 2 ) ^{2} - 4 \cdot 1 \cdot ( - 8 )}{2 \cdot 1}

(- 2)^{2} - 4 \cdot 1 \cdot (- 8) = 6

p_{1, 2} = \frac{- ( - 2 ) \pm 6}{2 \cdot 1}

解を分離する

p_{1} = \frac{- ( - 2 ) + 6}{2 \cdot 1}, p_{2} = \frac{- ( - 2 ) - 6}{2 \cdot 1}

p = \frac{- ( - 2 ) + 6}{2 \cdot 1} : 4

p = \frac{- ( - 2 ) - 6}{2 \cdot 1} : - 2

二次equationの解:

p = 4, p = - 2