n=[-10:9];x4=[1,0,1,2,3];xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';subplot(2,2,4);stem(n,xtilde);xlabel('n');ylabel('x4(n)');axis([-10,9,-1,4])请问,xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';怎么理解呢

来源：学生作业帮助网 编辑：作业帮 时间：2024/04/28 08:46:49
n=[-10:9];x4=[1,0,1,2,3];xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';subplot(2,2,4);stem(n,xtilde);xlabel('n');ylabel('x4(n)');axis([-10,9,-1,4])请问,xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';怎么理解呢

n=[-10:9];x4=[1,0,1,2,3];xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';subplot(2,2,4);stem(n,xtilde);xlabel('n');ylabel('x4(n)');axis([-10,9,-1,4])请问,xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';怎么理解呢
n=[-10:9];x4=[1,0,1,2,3];xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';
subplot(2,2,4);stem(n,xtilde);xlabel('n');
ylabel('x4(n)');axis([-10,9,-1,4])
请问,xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';怎么理解呢

n=[-10:9];x4=[1,0,1,2,3];xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';subplot(2,2,4);stem(n,xtilde);xlabel('n');ylabel('x4(n)');axis([-10,9,-1,4])请问,xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';怎么理解呢
xtilde=x4'*ones(1,4),是将x4转置变为一个列向量,再乘以一个一行4列的全1矩阵,这样会得到一个5行4列的矩阵
xtilde =
1 1 1 1
0 0 0 0
1 1 1 1
2 2 2 2
3 3 3 3
xtilde=(xtilde(:))'是将xtilde中的所有元素拉伸成一列,再转置为一行.
xtilde =
1 0 1 2 3 1 0 1 2 3 1 0 1 2 3 1 0 1 2 3

n=[-10:9];x4=[1,0,1,2,3];xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';subplot(2,2,4);stem(n,xtilde);xlabel('n');ylabel('x4(n)');axis([-10,9,-1,4])请问,xtilde=x4'*ones(1,4);xtilde=(xtilde(:))';怎么理解呢 1x2+2x3+3x4...+10x11=?1x2+2x3+3x4...+nx(n-1)=? 已知x2+x+1=0 求x4+1/x4 已知x2-x-1=0,求x4+1/x4 1x2+2x3+3x4+4x5+.+n(n+1)+n(n+2)=? 1x2=三分之一｛1x2x3-0x1x2｝；2x3-三分之一｛2x3x4-1x2x3｝：3x4-三分之一｛3x4x5-2x3x4}.由三个等式相加,可得1x2+2x3+3x4=三分之一x3x4x5=20问｛1｝1x2+2x3+3x4+.+10x11｛写出过程｝；｛2｝1x2+2x3+3x4...+n乘{n+1} 1x2+2x3+3x4+.+n(n+1)=_____(n为自然数） X1+X2-3X3-X4=1 3X1-X2-3X3+4X4=4 X1+5X2-9X3-8X4=0 解线性方程组 求非其次线性方程组 X1+X2-3X3-X4=1 3X1-X2-3X3+4X4=4 X1+X2-9X3-8X4=0 lingo软件求教max=1/2*x1*x2*@sin(x4)+1/2*x2*x3*@sin(120-x4);x4>0;x4 求Sn=1/1x2+1/2x3+1/3x4+.+1/n(n+1) 1X2X3+2X3X4+3X4+.+nx(n+1)(n+2)= 1x2+2x3+3x4+...+n（n+1）=? 1X2+2X4+3X8+.N X 2的N次方=? 1x4+4x7+7x11+……+n(n+3)=?分解因式啊~~~ X1-X2-3X3+X4=1 X1-X2+2X3-X4=3 2X1-2X2-11X3+4X4=0 4X1-4X2+3X3-2X4=10 用消元法 解线性方程组 求齐次线性方程组 x1-x2+5x3-x4=0;x1+x2-2x3+3x4=0;3x1-x2+8x3+x4=0;x1+3x2-9x3+7x4=0.基础解系和通解?得到等价方程组为：x1=-3/2*x3-x4;x2=7/2x3-2x4.此时令x3=1,x4=0,得到x1,x2,进而得到基础解系,再令x3=0,x4=1,得到x1,x2, 1x2+2x3+3x4+…+10x11=?1x2=1/3(1x2x3-0x1x2)2x3=1/3(2x3x4-1x2x3)3x4=1/3(3x4x5-2x3x4)1x2+2x3+3x4=1/3x3x4x5=201x2+2x3+3x4+…+n(n+1)=?《2010汕头中考》1x2x3+2x3x4+3x4x5+....+7x8x9=?