r^2-2r-3=0

解

r^{2} - 2 r - 3 = 0

r = 3, r = - 1

解答ステップ

r^{2} - 2 r - 3 = 0

解くとthe二次式

r_{1, 2} = \frac{- ( - 2 ) \pm ( - 2 ) ^{2} - 4 \cdot 1 \cdot ( - 3 )}{2 \cdot 1}

(- 2)^{2} - 4 \cdot 1 \cdot (- 3) = 4

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

解を分離する

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

r = \frac{- ( - 2 ) + 4}{2 \cdot 1} : 3

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

二次equationの解:

r = 3, r = - 1