在(1-2x)5的展开式中的x3的系数是().
A: 40
B: 80
C: -80
D: -40
A: 40
B: 80
C: -80
D: -40
举一反三
- (3-2x)^5的展开式中,x^3的系数是多少
- 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: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) - {1 \over {24}}(x - 4)(x - 9)\)
- 在(x2+2)5的展开式中x4的系数是______. A: 10 B: 10x4 C: 80 D: 80x4
- 函数$\sin^2 x$的麦克劳林级数展开式中$x^2$项的系数为 A: $-2$ B: $-1$ C: $0$ D: $1$
- 若f(x)=1/x2,则f(x)的导数是()。 A: 1/x3 B: -1/x3 C: 2/x3 D: -2/x3