MATLAB课后实验答案.docx

第四章作业4.1、a=input(请输入一个4位数:);while (a9999)a=input(输入错误，请重新输入一个4位数:);endb=fix(a/1000);c=rem(fix(a/100),10);d=rem(fix(a/10),10);e=rem(a,10);b=b+7;c=c+7;d=d+7;e=e+7;b=rem(b,10);c=rem(c,10);d=rem(c,10);e=rem(e,10);g=b;b=d;d=g;g=c;c=e;e=g;a=1000*d+100*e+10*b+c;disp(加密后：,num2str(a)4.2、a=input(请输入a: );b=input(请输入b: );c=input(请输入c: );x=0.5:1:5.5;x1=(x=0.5&x=1.5&x=3.5&x=5.5);y1=a.*(x.2)+b.*x+c;y2=a*(sin(b)c)+x;y3=log(abs(b+c./x);y=y1.*x1+y1.*x2+y3.*x3;disp(y)4.3、x=fix(rand(1,20)*89)+10;x1=fix(sum(x)/20);disp(平均数是：,num2str(x1)m=(rem(x,2)=0&x=ma=m;elseif b=mb=m;endenddisp(最小数是：,num2str(a)disp(最大数是：,num2str(b)4.5、s=0;a=0;for b=1:64c=2a;a=a+1;s=s+c;enddisp(2的0次方到63次方的和是：,num2str(s)4.6.1、sum1=0;for n=1:100x=(-1)(n+1)*(1/n);sum1=sum1+x;enddisp(当n取100时：sum=,num2str(sum1)sum2=0;for n=1:1000x=(-1)(n+1)*(1/n);sum2=sum2+x;enddisp(当n取1000时： sum=,num2str(sum2)sum3=0;for n=1:10000x=(-1)(n+1)*(1/n);sum3=sum3+x;enddisp(当n取10000时：sum=,num2str(sum3)4.8、clear alla=input(请输入一个矩阵：);b=input(请再输入一个矩阵：(注意：两矩阵要可以相乘);f1,f2=juzhenji(a,b);5.1x=-2*pi:pi/1000:2*pi;y=100./(1+x.2);plot(x,y)x=-2*pi:pi/1000:2*pi;y=(1/2*pi)*exp(-0.5*x.2);plot(x,y)t=-2*pi:pi/1000:2*pi;x=sin(t);y=cos(t);plot(x,y)t=-2*pi:pi/1000:2*pi;x=t.2;y=5*t.3;plot(x,y,r:)实验31、clearm=-5.0,-3.0,1.0,2.0,2.5,3.0,5.0;for x=mif x=0&x100|x120a=84*120+(y-120)*84*0.15;disp(您本月工资是：,num2str(a)elseif y5|n0b=a(5:5,:);disp(输入错误，程序输出最后一行的元素：,num2str(b)elsec=a(n:n,:);disp(输出结果是：,num2str(c)end实验41、n=input(“请输入n值：”)；s1=0;for k=1:n;x=1/(k2);s1=s1+x;pi=sqrt(6*s1);2、clearn=1;y=0;while (y3)x=1/(2*n-1);n=1+n;y=y+x;enddisp(y3时n的最大值是：,num2str(n-2)disp(相应的的y值是：,num2str(y-x)5、clearp=0;l=0;H=;for m=2:49a=m;b=m+1;c=a*b-1;for k=1:cif rem(c,k)=0l=l+1;endendif l=2disp(亲密数对是,(,num2str(a), ,num2str(b),)p=p+1;H=H,c;endl=0;endsum=sum(H);disp(亲密数对的个数是：,num2str(p)disp(亲密数对的和是：,num2str(sum)实验61、clear allx=linspace(0,2*pi,101);y=(0.5+3*sin(x)/(1+x.2).*cos(x);plot(x,y);title(y=0.5+3sin(x)/(1+x2)cos(x)的图像如下：)2/1 clear allx=linspace(-2*pi,2*pi,500);y1=x.2;y2=cos(2*x);y3=y1.*y2;plot(x,y1,b-,x,y2,r-,x,y3,k:);2/3 clear allx=linspace(-2*pi,2*pi,500);y1=x.2;y2=cos(2*x);y3=y1.*y2;subplot(3,3,1);bar(x,y1);%条形图subplot(3,3,2);stairs(x,y1);%阶梯图subplot(3,3,3);stem(x,y1);%杆图subplot(3,3,4);bar(x,y2);subplot(3,3,5);stairs(x,y2);subplot(3,3,6);stem(x,y2);subplot(3,3,7);bar(x,y3);subplot(3,3,8);stairs(x,y3);subplot(3,3,9);stem(x,y3);3、clear allt=linspace(-5,5,200);H=;for x=tif x0y1=0.5*log(x+sqrt(1+x.2);endH=H,y1;endplot(t,H,r:);4、clear alla=input(请输入一个数a：);b=input(请输入一个数b：);n=input(请输入一个数n：);theta=linspace(0,2*pi,500);rho=a*sin(b+n.*theta);polar(theta,rho);5、clear allx1=linspace(-5,5,21);y1=linspace(0,10,31);x,y=meshgrid(x1,y1);z=cos(x).*cos(y).*exp(-0.25.*sqrt(x.2+y.2)subplot(2,1,1);surf(x,y,z);subplot(2,1,2);contour3(x,y,z,30);6、clear alls=linspace(0,0.5*pi,10);t=linspace(0,1.5*pi,30);S,T=mes