rozwiaz rownanie
kasia: (x3−5)2−36=0
7 mar 11:31
Artur z miasta Neptuna:
(x3−5)2 − 36 = (x3−5)2 − 62 = (x3 − 5 −6)(x3 − 5 + 1) = (x3 − 11)(x3 + 1) = (*)
// (a3−b3) = (a−b)(a2+ab+b2)
// (a3 + b3) = (a+b)(a2−ab+b2)
(*) = (x−3√11)(x2+3√11x+3√121)(x+1)(x2−x+1)
więc: x=3√11 ⋁ x = −1
7 mar 11:40
kasia: ok dzieki
7 mar 11:53