Question

Determinati multimea valorilor functiei:
f:R-R, f(x)=x la patrat + x+1
f:(0,+ infinit),f(x)=x la patrat - 4x+1

Answer 1

f(x)=x² + x+1=(x+1/2)²+3/4≥3/4, ∨x∈R=> Imf=[3/4,+∞)

f(x)=x²- 4x+1=(x-2)²-3≥-3, ∨x∈(0,+∞)=>Imf=[-3,+∞)