x＜-2-2＜x＜-1-1＜x＜33＜x＜4x＞4x+2-++++x+1--+++x-3---++x-4----+（x+2）（x+1）（x-3）（x-4）+-
举一反三
- $(-x-1)(x^{4}+2x^{3}-x^{2}-4x-2)+(x+2)(x^{4}+x^{3}-x^{2}-2x-2)$的结果是（ ）。 A: $x^{2}-2$; B: $x^{3}-x^{2}-1$; C: $2x^{3}-4x-2$; D: $x^{4}+3x-2.$
- 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: $y={{C}_{1}}x+{{C}_{2}}x{{e}^{x}}-(\frac{1}{2}{{x}^{3}}+{{x}^{2}})$
- 方程（x＋1）（x－3）＝5的解是（）。 A: x<sub>1</sub>＝1，x<sub>2</sub>＝－3 B: x<sub>1</sub>＝4，x<sub>2</sub>＝－2 C: x<sub>1</sub>＝－1，x<sub>2</sub>＝3 D: x<sub>1</sub>＝－4，x<sub>2</sub>＝2
- 以4，9，1为为插值节点，求\(\sqrt x \)的lagrange的插值多项式 A: \( {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) + {1 \over {24}}(x - 4)(x - 9)\) B: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) + {1 \over {24}}(x - 4)(x - 9)\) C: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x +1) + {1 \over {24}}(x - 4)(x - 9)\) D: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) - {1 \over {24}}(x - 4)(x - 9)\)
- 求不定积分[img=112x35]17da6538063a9e4.png[/img]； （ ） A: (x^4*log(x)^2)/4 + (x^4*(log(x) - 1/4))/ B: (x^4*log(x)^2)/4 - (x^4*(log(x) - 1/4))/8 C: (x^4*log(x)^2)/4 - (x^4*(log(x) - 1/4)) D: (x^4*log(x)^2)/4 + (x^4*(log(x) - 1/4))/8