r^2+4r+3=0

解

r^{2} + 4 r + 3 = 0

r = - 1, r = - 3

解答ステップ

r^{2} + 4 r + 3 = 0

解くとthe二次式

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

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

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

解を分離する

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

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

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

二次equationの解:

r = - 1, r = - 3