Răspuns :
Δ=25-4*2*12=25-96=-71
[tex] x_{1} =\frac{5+ \sqrt{71i}}{4} x_{2} =\frac{5- \sqrt{71i}}{4} [/tex]
x2=(5-sqrt(71i))/4
x ∈ (-∞;[tex] x_{1} [/tex] ] U [[tex] x_{2} [/tex]; ∞]
[tex] x_{1} =\frac{5+ \sqrt{71i}}{4} x_{2} =\frac{5- \sqrt{71i}}{4} [/tex]
x2=(5-sqrt(71i))/4
x ∈ (-∞;[tex] x_{1} [/tex] ] U [[tex] x_{2} [/tex]; ∞]
2x2-5x+12=0
A=2
B=-5
C=12
Delta=b2-4ac
= (-5)2-4*2*12=25-96=-71 radacina imaginara aparatine multimii vide