共50条信息
设\(a\),\(b\),\(c\)为正数,且\(a+2b+3c=13\),则\(\sqrt{3a}+\sqrt{2b}+\sqrt{c}\)的最大值为\((\) \()\)
若\(a\),\(b\),\(c\),\(d\)都是实数,求证:\((a^{2}+b^{2})(c^{2}+d^{2})\geqslant (ac+bd)^{2}\),当且仅当\(ad=bc\)时,等号成立.
已知正数\(x\),\(y\),\(z\)满足\(x^{2}+y^{2}+z^{2}=6\).
\((\)Ⅰ\()\)求\(x+2y+z\)的最大值;
\((\)Ⅱ\()\)若不等式\(|a+1|-2a\geqslant x+2y+z\)对满足条件的\(x\),\(y\),\(z\)恒成立,求实数\(a\)的取值范围.
若实数\(x+y+z=1\),则\(2x^{2}+y^{2}+3z^{2}\) 的最小值为\((\) \()\)
已知\(x\),\(y\),\(z∈R\),且\(\dfrac{1}{x}+\dfrac{2}{y}+\dfrac{3}{z}=1\),则\(x+\dfrac{y}{2}+\dfrac{z}{3}\)的最小值是\((\) \()\)
已知\(x\),\(y\),\(z\)均为实数\(.\)若\(x+y+z=1\),求证:\( \sqrt{3x+1}+ \sqrt{3y+2}+ \sqrt{3z+3}\leqslant 3 \sqrt{3}\).
进入组卷