17e448c7400a56f.png一元二次方程求根公式的Python表达式写法正确的是:
A: x = (-b + (b * b - 4 * a * c) ** 1 / 2) / 2 * a
B: x = (-b + (b * b - 4 * a * c) ** (1 / 2)) / 2 * a
C: x = (-b + (b * b - 4 * a * c) ** (1 / 2)) / (2 * a)
D: x = (-b + (b * b - 4 * a * c) ** 0.5) / (2 * a)
A: x = (-b + (b * b - 4 * a * c) ** 1 / 2) / 2 * a
B: x = (-b + (b * b - 4 * a * c) ** (1 / 2)) / 2 * a
C: x = (-b + (b * b - 4 * a * c) ** (1 / 2)) / (2 * a)
D: x = (-b + (b * b - 4 * a * c) ** 0.5) / (2 * a)
举一反三
- 一元二次方程x(x-4)=-4的根是()。 A: -2 B: 2 C: 2或-2 D: -1或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: $y={{C}_{1}}x+{{C}_{2}}x{{e}^{x}}-(\frac{1}{2}{{x}^{3}}+{{x}^{2}})$
- 经计算整式x+1与x-4的积为x<sup>2</sup>-3x-4,则一元二次方程x<sup>2</sup>-3x-4=0的根是()。 A: x<sub>1</sub>=-1,x<sub>2</sub>=-4 B: x<sub>1</sub>=-1,x<sub>2</sub>=4 C: x<sub>1</sub>=1,x<sub>2</sub>=4 D: x<sub>1</sub>=1,x<sub>2</sub>=-4
- 设随机变量X~π(2),则E(X)= ( ). A: 1 B: 1/4 C: 1/2 D: 2
- 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