1 . x - ∞ 2 3 + ∞
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x -2 - - 0 + + +
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3 -x + + + + 0 - - -
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ex. - - 0 + I - -
poz. inZ daca x =2
2. x² + x - 2 < 0 Δ = 1 +8 =9
x₁= ( -1 -3) /2 = -4 /2 = -2
x₂ =( -1 + 3) /2 = 2 /2 =1
solutia x ∈ ( -2 , 1 ) cu numere naturale x = 0
