共50条信息
当\(x > 1\)时,函数\(y=x+\dfrac{1}{x\mathrm{{-}}1}\)的最小值是____\(.\)
已知变量\(x\),\(y\)满足约束条件\(\begin{cases}3x-y-6\leqslant 0 \\ x-y+2\geqslant 0 \\ x\geqslant 0 \\ y\geqslant 0\end{cases} \)若目标函数\(z=ax+by(a > 0,b > 0)\)的最大值为\(12\),求\( \dfrac{2}{a}+ \dfrac{3}{b} \)的最小值.
若\(a{ > }0{,}b{ > }0\),且函数\(f(x){=}4x^{3}{-}ax^{2}{-}2{bx}{+}2\)在\(x{=}2\)处有极值,则\(ab\)的最大值等于___________
下列函数中,最小值是\(2\)的是\((\) \()\)
证明下列不等式:
\((1)\)当\(a > 2 \)时,求证:\( \sqrt{a+2}+ \sqrt{a-2} < 2 \sqrt{a} \);
\((2)\)设\(a > 0\),\(b > 0\),若\(a+b-ab=0 \),求证:\(a+b⩾4 \).
已知关于\(x\)的不等式\(\left| x+1 \right|+\left| 2x-1 \right|\leqslant 3\)的解集为\(\left\{ x\left| m\leqslant x\leqslant n \right. \right\}\).
\((\)Ⅰ\()\)求实数\(m,n\)的值;
\((\)Ⅱ\()\)设\(a,b,c\)均为正数,且\(a+b+c=n-m\),求\(\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}\)的最小值.
已知\(a > 0\),\(ab=1\),则\(\dfrac{{{a}^{2}}+{{b}^{2}}}{a-b}\)的最小值是\((\) \()\)
在\(\triangle ABC\)中,角\(A\),\(B\),\(C\)所对的边分别为\(a\),\(b\),\(c\),若\(\sin \left( \dfrac{3}{2}B+\dfrac{{ }\!\!\pi\!\!{ }}{4} \right)=\dfrac{\sqrt{2}}{2}\),且\(a+c=2\),则\(\triangle ABC\)周长的取值范围是_______.
设正数\(x\),\(y\)满足\(x+2y=2\),则\(\dfrac{2}{x}{+}\dfrac{1}{y}\)的最小值为_________.
进入组卷