Question

TÌM GTNN: x^2 + x-5

Answer 1

\(A=x^2+x+\dfrac{1}{4}-\dfrac{21}{4}=\left(x+\dfrac{1}{2}\right)^2-\dfrac{21}{4}\ge-\dfrac{21}{4}\forall x\)

Dấu '=' xảy ra khi x=-1/2