MATLAB仿真及电子信息应用答案

1、5 / 7MATLAB仿真及电子信息应用第二单元1. a=zeros(2) a =0 00 0 a(1,2)=2a =0 20 02. a=1 0 -2 3;b=0 1 2 1; a+b ans =1 1 0 4 a.*bans =0 0 -43 /-4+3 =-1 dot(a,b)ans =-13. a=randn(4)0.81561.1908-1.6041-0.80510.7119-1.20250.25730.52871.2902-0.0198-1.05650.21930.6686-0.15671.4151-0.9219 sum(diag(a)ans =-2.3652 reshape(a,

2、2,8) ans =0.81561.29021.1908-0.0198-1.6041-1.0565-0.80510.21930.71190.6686-1.2025-0.15670.25731.41510.5287-0.92194. a=rand(3,5) a =0.95010.48600.45650.44470.92180.23110.89130.01850.61540.73820.60680.76210.82140.79190.1763 a(:,4)=a(:,4)+0.20.95010.48600.45650.64470.92180.23110.89130.01850.81540.73820

3、.60680.76210.82140.99190.1763 lt(a,0.5)ans =0110010100000015. a=randn(3,2);b=randn(3,2); cat(1,a,b) / 按列方向ans =0.73100.67710.57790.56890.0403-0.2556-0.3775-0.2340-0.29590.1184-1.47510.3148cat(2,a,b)/ 按行方向ans =0.73100.6771-0.3775-0.23400.57790.5689-0.29590.11840.0403-0.2556-1.47510.31486. Hello every

4、oneans =Hello everyone7. str1=MATLAB ;str2 =is strong;str3=str1,str2 str3 =MATLAB is strong8.(1) 直接法 a=Function Variable;y=f(x) x;6 1:5Function Variabley=f(x) x6 1x5 double(2) 函数法 a=cell(3,2);a1,1=Function;a1,2=Variable; a2,1=y=f(x);a2,2=x; a3,1=6;a3,2=1:5; aFunctionVariabley=f(x)x61x5 double9.stude

5、nt1.Name=Mary;student1.Age=Eighteen;student1.Score=502;student1.Class=1;student1 student1 =Name: MaryAge: EighteenScore: 502Class: 1 student2.Name=Mike;student2.Age=Nighteen; student2.Score=498;student2.Class=2; student2student2 =Name: MikeAge: NighteenScore: 498Class: 2 student3.Name=Joe;student3.A

6、ge=Eighteen; student3.Score=520;student3.Class=3;student3student3 =Name: JoeAge: EighteenScore: 520Class: 3第三单元3-1 clear all clc p=5 4 1 2 1;roots(p) %求根 y=polyval(p,5)%求在 5 处函数的函数值3-2 clear all clc p=2 0 -2 5;x=1 2 4;-1 0 3;5 2 1;f=polyder(p)%多项式求导polyvalm(p,x)3-3 clear all clcf=factor(sym(2*xA4-5*

7、xA3+4*xA2-5*x+2)3-4clear allclc f1=sym(xA2+1)(x-2);f2=sym(2*xA2+1);f=expand(f1*f2)3-5 clear all clcsyms x y;f=log(1+x);g=2*sin(y);compose(f,g)compose(g,f)3-6 clear all clc syms x ;finverse(cos(1+x)3-7(1) (2) clear all clcsyms x y k;f1=(1/2Ax)+(-1)Ax/xA2);f2=1/(1+kA2) 1/(2*k+1) s1=symsum(f1,1,inf)s2=

8、symsum(f2,1,inf)(3) (4)(5)(6) clear all clcsyms x ;f1=(1+2Ax)A(1/x); f2=(xA2)*exp(1/xA2); f3=log(tan(x)/sin(x); f4=(x/(2*x+1)A(x-1);limit(f1,inf) limit(f2,0) limit(f3,x,0,right)limit(f4,inf)(7)(8)clear all clc syms x y z a b;f1=1/(1+xA2);f2=(xA2+yA2+zA2);int(f1,x,a,b)int(int(int(f2,z,sqrt(x*y),x*y),

9、y,sqrt(x),x),x,0,1) 3-8 clear all clc syms x;f=x*exp(x) log(si n(x);1 /(1+xA2) xA(3/2); diff(f,2)3-9(1) clear all clc f=sym(xA3-2*x+5);solve(f)(2) clear all clc syms x1 x2 x3;f1=2*x1-5*x2+3; f2=5*x1-2*x2+18;x1 x2=solve(f1,f2)(3) 方法一： clear all clcsyms x1 x2 x3;f1=3*x1+11*x2-2*x3-8; f2=1*x1+1*x2-2*x3+4;f3=x1-x2+x3-3;x1 x2 x3=solve(f1,f2,f3) 方法二： clear allclcA=3 11 -2;1 1 -2;1 -1 1;B=8;-4;3;x=AB(4) clear all clcsyms x1 x2 x3;f1=2*x1-x2-exp(-x1); f2