CMR:
\(-\dfrac{1}{2}-x^2+x< 0\) ∀ \(x\)
Cho a,b>0 thoả mãn a+b\(\le1\)
CMR: \(\frac{1}{a^2+b^2}+\frac{2}{ab}+4ab\ge11\)
CMR \(\dfrac{-1}{2}-x^2+x< 0\forall x\)
CMR: \(x-x^2-1< 0\forall x\)
CMR A= x\(^4\) - 12x\(^3\) + 46x\(^2\) - 60x + 25 \(\ge\) 0, \(\forall\)x
CMR A = x\(^4\) -12x\(^3\) + 46x\(^2\) - 60x + 25 \(\ge\) 0 \(\forall\)x
CMR \(x^2-5xy+z^2+10y^2+2>0\forall x,y,z\)
CMR
\(-4+5-x^2< 0\forall x\)
CMR: \(\sqrt{a^2+b^2}\ge\dfrac{a+b}{\sqrt{2}}\) với a,b >0