Question

Sllutia naturala a inecuatiei xla2 +x-2<0 este ? Ofer coronita

Answer 1

x² + x - 2 < 0
se rezolva ecuatia de gr. II
X² + X - 2 = 0
a = 1, b = 1, c= - 2
Δ = b² - 4ac = 1² - 4·1· ( - 2)
Δ = 1 + 8 = 9
Δ = 9 ( > 0), deci avem doua solutii destincte
x1 = ( - b - √Δ) / 2a = ( - 1 - √9) / 2·1 = ( - 1 - 3) / 2 = - 4 / 2 = - 2
x1 = - 2
x2 = ( - b + √Δ) /2a = ( - 1 + 3 ) / 2 = 2 / 2 = 1
x2 = 1
revenim la inecuatie
x² + x - 2< 0, solutii x1 = - 2, x2 = 1
 x ∈ ( - 2 , 1) ∧ N
x ∈ { 0}