MATLAB仿真及电子信息应用答案

1、1/ 7MATLAB仿真及电子信息应用第二单元1.a=zeros(2) a =0000 a(l,2)=202002. a=l 0 -2 3;b=0 1 2 1; a+b ans =1104 a.*bans =0 0 dot(a,b)ans =-13. a=randn(4)1.1908-1.2025-0.0198-0.1567-1.60410.2573-1.05651.4151-0.80510.52870.2193-0.9219sum(diag(a)-43 4+3 =-l0.81560.71191.29020.66862/ 7ans =-2.3652reshape(a,2,8)ans =0.81

2、561.29020.71190.66864. a=rand(3/5)a 1.1908-1.2025-0.0198-0.1567-1.60410.2573-1.05651.4151-0.80510.52870.2193-0.9219a 0.95010.48600.45650.44470.92180.23110.89130.01850.61540.73820.60680.76210.82140.79190.1763 a(:,4)=a(:z4)+0.20.95010.48600.45650.64470.92180.23110.89130.01850.81540.73820.60680.76210.8

3、2140.99190.1763lt(a,0.5)ans =0 11010 100 0 0 05. a=randn(3,2);b=randn2); cat(lab) 按列方向ans =0.73100.57790.0403-0.3775-0.2959-1.4751 cat(2,a,b)0.67710.5689-0.2556-0.23400.11840.3148按行方向3/ 7ans =0.73100.6771-0.3775-0.23400.57790.5689-0.29590.11840.0403-0.2556-1.47510.31486. Hello everyoneans =Hello eve

4、ryone7. strl=,MATLAB ;str2 =is strong,;str3=strl/str2str3 =MATLAB is strong8.直接法 a 二Function,Variable,;,y=f(x) 1:5Function* Variabley=f(x)乂61x5 double(2)函数法 a=cell(3/2);al,l=，Function,;al/2=,Variable,; a2/l=y=f(x);a2/2=x,; a3,l=，6,;a3,2=l:5; aFunction* Variabley=f(x)乂61x5 double9.studentl.Name=Mary,

5、;studentl.Age=,Eighteen;studentl.Score=,502,;studentl.Class=,l;studentl stude ntl=Name: Mary4/ 7Age: EighteenScore: 502Class:lll student2.Name=,Mike,;student2.Age=,Nighteen,; student2.Score=l498,;student2.Class=,2,; student2stude nt2 =Name: MikeAge: Nighteen1Score: 4981Class: 2 student3.Name=,Joe,;s

6、tudent3Age=Eighteen； student3.Score=,520l;student3.Class=,3,;student3stude nt3 =Name: Joe*Age: EighteenScore: *520Class: 3第三单元3-1clear allclcP=5 4 12 1;roots(p) % 求根y=polyval(p,5) %求在 5 处函数的函数值3-2clear allclcP=2 0-2 5;x=l 2 4;-l 0 3;5 2 1;f=polyder(p) %多项式求导 polyvalm(p,x)3-3clear allclcf=factor(sym(

7、,2*xA4-5*xA3+4*xA2-5*x+2,)3-4clear allclcfl=sym(,(xA2+l)(x-2)1)；5/ 7f2=sym(,2*xA2+l,); f=expand(fl*f2) 3-5clear allclcsyms x y; f=log(l+x); g=2*sin(y);compose(f,g) compose(g,f) 3-6clear allclc syms x;fi nv erse(cos(l+x)3-7(1) (2)clear allclcsyms x y k;fl=(V2Ax)+(-l)Ax/xA2);f2=V(l+kA2) V(2*k+1)sl=sym

8、sum(fl,l,inf)s2=symsum(f2,l,i nf)(3) (4) (5) (6) clear allclcsyms x;fl=(l+2Ax)A(Vx)；f2=(xA2)*exp(l/xA2);f3=log(tan(x)/sin(x);f4=(x/(2*x+l)A(x-l);limit(fljnf)limit(f2,0)limit(f3,x,0/,right)Iimit(f4zinf)(7) (8)clear allclcsyms x y z a b;fl=l/(l+xA2);f2=(xA2+yA2+zA2);int(fl,x,a,b) int(int(int(f2/z/sqrt

9、(x*y)/x*y),y/sqrt(x)/x)/x,0/l)3-8clear allclcsyms x;f=(x*exp(x) log(sin(x);l/(l+xA2) xA(2)；diff(f,2)3-9(1)clear allclc6/7f=sym(,xA3-2*x+5,);solve(f)(2)clear allclcsymsxlx2 x3;fl=2*xl-5*x2+3; f2=5*xl-2*x2+18;xl x2=solve(fl,f2)(3)方法一：clear allclcsymsxlx2 x3; fl=3*xl+ll*x2-2*x3-8; f2=l*xl+l*x2-2*x3+4;f3=xl-x2+x3-3;xl x2 x3=solve(fl/f2/f3)方法二：clear allclcA=3 11 -2;11 -2;1 -11;B=8;-4;3J;x=AB(4)clear allclcsyms xl x2 x3;fl=2*xl-x2-exp(-xl);f2=xl