MATLAB计算序列x[n]的能量的语句错误的是
A: sum(x.*conj(x))
B: sum( abs(x) .^2 )
C: sum(x.^2 )
D: sum(real(x).^2+imag(x).^2 )
A: sum(x.*conj(x))
B: sum( abs(x) .^2 )
C: sum(x.^2 )
D: sum(real(x).^2+imag(x).^2 )
举一反三
- 对于给定非负整数[img=11x14]17de86c7a4e3414.png[/img]，计算[img=132x24]17de86c7b1aebe2.png[/img]的方法是 A: [x^2 | x - [1..n]] B: sum[x^2 | x - [1..n]] C: sum [x | x^2 - [1..n]] D: sum [x | x - [1..n^2]] E: sum [y | y- [1..n], y = x^2] F: sum [ x*y | (x,y) - zip [1..n] [1..n]] G: sum [ x*x | (x,x) - zip [1..n] [1..n]]
- 对于给定非负整数[img=11x14]1803c4615c4a826.png[/img]，计算[img=132x24]1803c461653d41a.png[/img]的方法是 A: [x^2 | x - [1..n]] B: sum[x^2 | x - [1..n]] C: sum [x | x^2 - [1..n]] D: sum [x | x - [1..n^2]] E: sum [y | y- [1..n], y = x^2] F: sum [ x*y | (x,y) - zip [1..n] [1..n]] G: sum [ x*x | (x,x) - zip [1..n] [1..n]]
- 将\(f(x) = {1 \over {2 - x}}\)展开成\(x \)的幂级数为（ ）。 A: \({1 \over {2 - x}} = \sum\limits_{n = 0}^\infty { { { { x^n}} \over { { 2^{n }}}}} \)，\(( - 2,2)\) B: \({1 \over {2 - x}} = \sum\limits_{n = 0}^\infty { { { { x^n}} \over { { 2^{n }}}}} \)，\(\left( { - 2,2} \right]\) C: \({1 \over {2 - x}} = \sum\limits_{n = 0}^\infty { { { { x^n}} \over { { 2^{n + 1}}}}} \)，\(( - 2,2)\) D: \({1 \over {2 - x}} = \sum\limits_{n = 0}^\infty { { { { x^n}} \over { { 2^{n + 1}}}}} \)，\(\left( { - 2,2} \right]\)
- 已知x=[1;2],A=[111;248],在Matlab中可由x生成A的命令为 A: A=[x,x^2,x^3] B: A=[x;x^2;x^3] C: A=[x;x^2;x^3] D: A=[x,x.^2,x.^3]
- 已知[img=52x29]18038be96ed0534.png[/img]，[img=115x51]18038be97866e95.png[/img]，在MATLAB中若想由x生成矩阵A可调用命令 A: A=[x,x.^2,x.^3] B: A=[x,x^2,x^3] C: A=[x;x.^2;x.^3] D: A=[x;x^2;x^3]