4a^2-4a-8=0

解

4 a^{2} - 4 a - 8 = 0

a = 2, a = - 1

解答ステップ

4 a^{2} - 4 a - 8 = 0

解くとthe二次式

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

(- 4)^{2} - 4 \cdot 4 (- 8) = 12

a_{1, 2} = \frac{- ( - 4 ) \pm 12}{2 \cdot 4}

解を分離する

a_{1} = \frac{- ( - 4 ) + 12}{2 \cdot 4}, a_{2} = \frac{- ( - 4 ) - 12}{2 \cdot 4}

a = \frac{- ( - 4 ) + 12}{2 \cdot 4} : 2

a = \frac{- ( - 4 ) - 12}{2 \cdot 4} : - 1

二次equationの解:

a = 2, a = - 1