设［X］补=1.x1x2x3x4,当满足______时，X > -1/2成立。
举一反三
- 设A={x|-1<x<2},B={x|1<x<3},求A∪B. A: {x|-1<x<2} B: {x|-1<x<1} C: {x|-1<x<3} D: {x|2<x<3}
- 已经随机变量x满足e(x)=1,d(x)=2,则e(x²)=,1?2?3?4?
- 设集合A={x丨-1＜x＜2}，B={x丨1＜x＜3}，则A∪B=______． A: {x丨-1＜x＜2} B: {x丨1＜x＜3} C: {x丨1＜x＜2} D: {x丨-1＜x＜3}
- 设[X]原码=1.X1X2X3X4,当满足（）时，X〉-0.5成立
- 方程${{x}^{2}}{{y}^{''}}-(x+2)(x{{y}^{'}}-y)={{x}^{4}}$的通解是( ) A: $y={{C}_{1}}x+{{C}_{2}}{{e}^{x}}-(\frac{1}{2}{{x}^{3}}+{{x}^{2}})$ B: $y={{C}_{1}}x+{{C}_{2}}{{e}^{x}}-(\frac{1}{2}{{x}^{3}}+{{x}^{4}})$ C: $y={{C}_{1}}x+{{C}_{2}}x{{e}^{x}}-(\frac{1}{2}{{x}^{3}}+{{x}^{4}})$ D: $y={{C}_{1}}x+{{C}_{2}}x{{e}^{x}}-(\frac{1}{2}{{x}^{3}}+{{x}^{2}})$