Question

MATLAB 7.是一个维m ×n的矩阵,写一段程序,算出A 中有多少个零元素.8.解方程(组),(1) x+2y+z=

Answer 1

%----------------------------------------

% Made By mcm_ma

% 2010.6.18

%

%------------计算A中的0的个数------------

SUM = sum(sum(A==0))

%------------解方程组--------------------

A = [1 2 1;2 1 -2;3 -4 2];

b = [1 3 9]';

Ab

%------------解微分方程（解析解）--------------------

y = dsolve('Dy=a*y','x')

yt = dsolve('Dy=a*y','y(0)=b','x')