设[tex=2.357x1.214]+x8uP9rU2haZldBo3xOilAezUmo1AAbTuf/D9WU6ZPM=[/tex]分别是图所示放大电路的上限截止频率和下限截止频率。当[tex=1.071x1.214]ivLvhgw/pbLc9KUPF9nt4g==[/tex]增大时，[tex=2.5x1.214]n5t/QRZRJRkt8U2JJg/OCQ==[/tex]怎么变化？[img=382x270]17a1483f52fdfc2.png[/img]
举一反三
- \(二次型f（x）=x^{T}\begin{bmatrix} 1 & 2 & 3 \\ 4 & 5 & 6 \\ 7 & 8 & 9 \end{bmatrix}x的秩为\)
- 已知某电路的波特图如图所示[img=463x427]179db6ca46f338a.png[/img]电路的下限频率 [tex=1.0x1.214]15MguWHbXdgQyy84msdfrQ==[/tex]上限频率[tex=1.071x1.214]lA4P+YAMGZaLoqXuGz5yng==[/tex]
- 设X ~ N(2, 9)则Y = (X – 2 )/9 ~ N(0, 1).
- 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: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) - {1 \over {24}}(x - 4)(x - 9)\)
- 与数学式子[img=43x34]17e0acb62c85ed0.jpg[/img]对应的C语言表达式是 A: 9*x^n/(2*x-1) B: 9*x**n/(2*x-1) C: 9*pow(x,n)*(1/(2*x-1)) D: 9*pow(n,x)/(2*x-1)