|x^2+2x|=1

解

x^{2} + 2 x = 1

x = - 1 - 2 or x = - 1 or x = - 1 + 2

十進法表記

x = - 2.41421 \dots, x = - 1, x = 0.41421 \dots

解答ステップ

x^{2} + 2 x = 1

絶対規則を適用する:

∣ u ∣ = a, a > 0

の場合は

u = a

u = - a

x^{2} + 2 x = - 1 or x^{2} + 2 x = 1

x^{2} + 2 x = - 1 or x^{2} + 2 x = 1

x = - 1 or (x = - 1 - 2 or x = - 1 + 2)

x = - 1 - 2 or x = - 1 or x = - 1 + 2