Question

Fie A multimea solutiilor reale ale ecuatiei -6x²-x+2=0.determinati A∩[-1/2;1]

Answer 1

Δ=b²-4ac=1+48=49
x1=(+1+7)/(-12)=-8/12=-2/3
x2=(+1-7)/(-12)=+6/12=1/2
A={-2/3, 1/2}
A∩[-1/2, 1]={-2/3, 1/2}∩[-1/2, 1]={1/2}