MATLAB程序设计教程第二版课后答案

1、MATLAB第二版课后答案unit3-8unit3实验指导1、n=input('请输入一个三位数：,);a=fix(n/100);b=fix(n-a*100)/10);c=n-a*100-b*10;d=c*100+b*10+a2 (1)n=input(,请输入成绩,);switch ncase num2cell(90:100)p='A'case num2cell(80:89)p='B'case num2cell(70:79)p='C'case num2cell(60:69)p='D'otherwisep='E

2、9;endprice=p(2) n=input(,请输入成绩,);if n>=90&n<=100p='A'elseif n>=80&n<=89p='B'elseif n>=70&n<=79P='C'elseif n>=60&n<=69p='D'elseP='E'endprice=p(3) tryn;catchprice='erroe'end3n=1,5,56,4,3,476,45,6,3,76,45,6,4,3,6,4,

3、23,76,908,6;a=n；b=n；for m=2:20if n(m)>aa=n(m);elseif n(m)<bb=n(m);endend max=amin=b法2n=1,5,56,4,3,476,45,6,3,76,45,6,4,3,6,4,23,76,908,6;min=min(n)max=max(n)4b=：;for n=1:61a=b(n);y(n)=(exp*a)-exp*a)/2*sin(a+log(+a)/2);endy5y1=0;y2=1;n=input(' 请输入n的值：');for i=1:ny1=y1+1/iA2;y2=y2*(4*i*i

4、)/(2*i-1)*(2*i+1);endy1y26A=1,1,1,1,1,1;2,2,2,2,2,2;3,3,3,3,3,3;4,4,4,4,4,4;5,5,5,5,5,5;6,6,6,6,6,6; n=input(' 请输入n的值:');if n<=5&n>=0disp(A(n,:);elseif n<0disp(lasterr);else disp(A(6,:);disp(lasterr);end7 (1)f=；for n=1:40f(n)=n+10*log(nA2+5);endy=f(40)/(f(30)+f(20)f=;a=0;for n=1

5、:40f(n)=a+n*(n+1);a=f(n);endy=f(40)/(f(30)+f(20)8y=0;m=input('输入 m的值:');n=input('输入 n 值：');for i=1:ny=y+iAm;endy*function s=shi8_1(n,m)s=0;for i=1:ns=s+iAm;end*shi8_1(100,1)+shi8_1(50,2)+shi8_1(10,1/2)思考练习2N=1,2,3,4,5;2.*NN./21 ./N2 ./N.A23s=fix(100*rand(1,20)*9/10+10)y=sum(s)/20j=0；

6、for i=1:20if s(i)<y&rem(s(i),2)=0j=j+1；A(j)=s(i);else continue;endendAy1=0;y2=0;n=input('请输入n的值：');for i=1:ny1=y1+-(-1)Ai/(2*i-1);y2=y2+1/4Ai;endy1y2unit4实验指导3 (1)x=-10:10;y=x-x.A3./6;Plot(x,y)x=-10:10;ezplot('xA2+2*yA2-64',-8,8);grid on;4t=-pi:pi/10:pi;y=1./(1+exp(-t);subplot

7、(2,2,1);bar(t,y);title('条形图(t,y),);axis(-pi,pi,0,1);subplot(2,2,2);stairs(t,y,'b');title(' 阶梯图(t,y),);axis(-pi,pi,0,1);subplot(2,2,3);stem(t,y,'k');title('杆图(t,y),);axis(-pi,pi,0,1);subplot(2,2,4);loglog(t,y,'y');title('对数坐标图(t,y)');5 (1)t=0:pi/50:2*pi;r=5

8、.*cos(t)+4;polar(t,r);title('rho=5*costheta+4');t=-pi/3:pi/50:pi/3;r=5.*(sin(t).A2)./cos(t);polar(t,r);6 (1)t=0:pi/50:2*pi;x=exp(-t./20).*cos(t);y=exp(-t./20).*sin(t);z=t;plot3(x,y,z);grid on;x,y=meshgrid(-5:5);z=zeros(11)+5;mesh(x,y,z);shading interp;5x,y,z=sphere(20);surf(x,y,z);axis off;s

9、hading interp;m=moviein(20);for i=1:20axis(-i,i,-i,i,-i,i)m(:,i)=getframe;endmovie(m,4);思考练习7 (1)x=-5:5;y=(1./(2*pi).*exp(-(x.A2)/2);plot(x,y);t=-2*pi:2*pi;x=t.*sin(t);y=t.*cos(t);plot(x,y);grid on;8t=0:pi/1000:pi;x=sin(3.*t).*cos(t);y1=sin(3.*t).*sin(t);y2=2.*;plot(x,y1,'k',x,y2);hold on;k=

10、find(abs(y1-y2)<1e-2);x1=x(k);y3=2.*;plot(x1,y3,'rp');9x=-2:2;y=sin(1./x);subplot(2,1,1);plot(x,y);subplot(2,1,2);fplot('sin(1./x)',-2,2,1e-4);10 (1)i=-4*pi:10;j=12./sqrt(i);polar(i,j);title('rho=12/sqrt(theta),)a=-pi/6:pi/6;b=3.*asin(a).*cos(a)./(sin(a).A3+(cos(a).A3);polar(a

11、,b);11 (1)u,v=meshgrid(-4:4);x=3.*u.*sin(v);y=2.*u.*cos(v);z=4.*u.A2;subplot(2,1,1);mesh(x,y,z);subplot(2,1,2);surf(x,y,z);x,y=meshgrid(-3二3);z=-5./(1+x.A2+y.A2);subplot(1,2,1);mesh(x,y,z);subplot(1,2,2);surf(x,y,z);unit5实验指导1A=randn(10,5)x=mean(A)y=std(A)Max=max(max(A)Min=min(min(A)Sumhang=sum(A,2)

12、SumA=sum(Sumhang)B=sort(A);C=sort(B,2,'descend');C2 (1)a=0:15:90;b=a./180.*pi;s=sin(b)c=0:15:75;d=c./180.*pi;t=tan(d)e=input('请输入想计算的值：,);S=sin(e/180*pi)T=tan(e/180*pi)S1=interp1(a,s,e,'spline')T1=interp1(c,t,e,'spline')P1=polyfit(a,s,5);P2=polyfit(c,t,5);S2=polyval(P1,e)

13、T2=polyval(P2,e)n=1,9,16,25,36,49,64,81,100;N=sqrt(n);x=input('ji suan zhi :');interp1(n,N,x,'cubic')3N=64;T=5;t=linspace(0,T,N);h=exp(-t);dt=t(2)-t(1);f=1/dt;X=fft(t);F=X(1:N/2+1);f=f*(0:N/2)/N;plot(f,abs(F),'-*')4P=2,-3,0,5,13;Q=1,5,8;p=polyder(P) q=polyder(P,Q) a,b=polyder

14、(P,Q)5P1=1,2,4,0,5;P2=0,1,2;P3=1,2,3;P=P1+conv(P2,P3)X=roots(P)A=-1,;,2,;0,5,;p=polyval(P,A)思考练习4A=rand(1,30000);a=mean(A)b=std(A)Max=max(A)Min=min(A)n=0;for i=1:30000if(A(i)>n=n+1;endend ny=n/300005p=45,74,54,55,14;78,98,45,74,12;87,98,85,52,65M,S=max(p)N,H=min(p)junzhi=mean(p,1)fangcha=std(p,1,

15、1)zong=sum(p,2);Max,wei=max(zong)Min,wei=min(zong)zcj,xsxh=sort(zong,'descend')6x=1:10:101;y=0,;p,s=polyfit(x,y,5)a=1:5:101;y1=polyval(p,a);plot(x,y,':o',a,y1,'-*')unit6实验指导A=1/2,1/3,1/4;1/3,1/4,1/5;1/4,1/5,1/6;P=,'；x=ApA=1/2,1/3,1/4;1/3,1/4,1/5;1/4,1/5,1/6;P=,'；x=Apc

16、ond(A)2 (1)x1=fzero(funx1,-1)function fx=funx1(x)fx=xA41+xA3+1;x2=fzero(funx2,function fx=funx2(x)fx=x-sin(x)/x;3 3)options=optimset('Display','off);x=fsolve(fun3,1,1,1,options)q=fun3(x)function q=fun3(p)x=p(1);y=p(2);z=p(3);q(1)=sin(x)+yA2+log(z)-7;q(2)=3*x+2Ay-zA3+1;q(3)=x+y+z-5;3 (1)t

17、0=0;tf=5;y0=1;t,y=ode23(fun4,t0,tf,y0);t'y1function yp=fun4(t,y)yp=-+sin(10*t)*y;t0=0;tf=5;y0=1;t,y=ode23(fun5,t0,tf,y0);t'y1function yp=fun5(t,y)yp=cos(t)-y/(1+tA2);4x=fminbnd(mymin,0,2);-mymin(x)function fx=mymin(x)fx=-(1+x.A2)/(1+x.A4);5options=optimset('Display','offi);x,fval

18、=fmincon(fun6,0,0,0,a,b,lb,ub)-fvalfunction f=fun6(x)f=-(sqrt(x)+(400-x(1)*+(sqrt(x(2)+(400-x(1)*(2)*+sqrt(3)+(400-x )*(2)*(3)*+sqrt(x(x4);思考练习1 (1)A=2,3,5;3,7,4;1,-7,1;B=10,3,5'C1=inv(A)*BC2=ABL,U=lu(A);x=U(LB)A=6,5,-2,5;9,-1,4,-1;3,4,2,-2;3,-9,0,2;B=-4,13,1,11'C1=inv(A)*BC2=ABL,U=lu(A);x=U

19、(LB)2 (1)x1=fzero(funx1,function fx=funx1(x)fx=3*x+sin(x)-exp(x);x1=fzero(funx2,1)function fx=funx2(x)fx=x-1/x+5;3 3)options=optimset('Display','off);x=fsolve(fun3,3,0,options)q=fun3(x)function q=fun3(p)x=p(1);y=p(2);q(1)=xA2+yA2-9;q(2)=x+y-1;3 (1)t0=0;tf=5;y0=0,1;t,y=ode45(vdpol,t0,tf,y

20、0);t,yfunction ydot=vdpol(t,y);ydot(1)=(2-3*y(2)-2*t*y(1)./(1+tA2);ydot(2)=y(1);ydot=ydot't0=0;tf=5;y0=1;0;2;t,y=ode45(vdpoll,t0,tf,y0);t,yfunction ydot=vdpoll(t,y);ydot(1)=cos(t)-y(3)./(3+sin(t)+5*y(1).*cos(2*t)/(t+1).A2)-y(2);ydot(2)=y(1);ydot(3)=y(2);ydot=ydot'4x=fminbnd(mymin,0,pi);-mymi

21、n(x)function fx=mymin(x)fx=-sin(x)-cos(x.A2);5x,y1=fminbnd(mymax,0,;-y1function fx=mymax(x);fx=-(9*x+4*x.A3-12*x.A2);unit7实验指导1 (1)format longfx=inline('sin(x)./x');I,n=quadl(仅,0,2,1e-10)format longfx=inline('1./(.A2+-1./(.A2+-6');I,n=quad(fx,0,1,1e-10)2 (1)global ki;ki=0;1=如何皎或仅丫,0,

22、1,0,1)kif=inline('abs(cos(x+y)','x','y');I=dblquad(f,0,pi,0,pi)3Y , , , x-：；F=,;trapz(X,F)4p=0:pi/5:2*pi;for n=1:3DX=diff(sin(p),n)end5f=inline('sin(x)./(x+cos(2.*x)');g=inline('(cos(x).*(x+cos(2*x)-sin(x).*(1-2.*sin(2*x)/(x+cos(2.*x).A2') x=-pi:pi;p=polyfit(x

23、,f(x),5);dp=polyder(p);dpx=polyval(dp,x);求dp在假设点的函数值dx=diff(f(x,)/; % 直接对f(x)求数值导数gx=g(x);求函数f的导函数g在假设点的导数作图plot(x,dpx,x,dx,'.',x,gx,'-'); %思考练习2format longfx=inline('1./(1+x.A2),);I,n=quad(fx,-Inf,Inf,1e-10)I,n=quadl(fx,-Inf,Inf,1e-10)x=-100000:100000;y=1./(1+x.A2);trapz(x,y)for

24、mat short3(1)format longfx=inline('log(1+x)./(1+x.A2),);I,n=quad(fx,0,1,1e-10)(2)format longfx=inline('sqrt(cos(t.A2)+4*sin(2*t).A2)+1)');I,n=quad(fx,0,2*pi,1e-10)4f=inline('4.*x.*z.*exp(-z.A2.*y-x.A2),);I=triplequad(f,0,pi,0,pi,0,1)5f=inline('sin(x)');g=inline('cos(x)

25、9;);x=0:2*pi;p=polyfit(x,f(x),5);dp=polyder(p);dpx=polyval(dp,x);dx=diff(f(x,2*pi+)/;gx=g(x);plot(x,dpx,x,dx,'.',x,gx,'-')unit8实验指导1syms x y;s=xA4-yA4;factor(s)factor(5135)2syms x;f=(x-2)/(xA2-4);limit(f,x,2)sym x;f=(sqrt(pi)-sqrt(acos(x)/sqrt(x+1);limit(f,x,-1,'right')3sym x

26、;f=sin(1/x);diff(f,'x')sym x;f=(1-cos(2*x)/x;diff(f,'x')diff(f,'x',2)4sym x;f=sqrt(exp(x)+1);int(f,'x')syms x y;f=x/(x+y);int(f,'y')sym x;f=exp(x)*(1+exp(x)A2;int(f,'x',0,log(2)sym x;f=x*log(x);int(f,'x',1,exp(1)5sym x;s=symsum(-1)A(x+1)/x,1,In

27、f)sym y;z=symsum(yA(2*y-1)/(2*y-1),1,Inf) sym x;f1=(exp(x)+exp(-x)/2;f2=sqrt(xA3-2*x+1);taylor(f1,x,5,0)taylor(f2,x,6,0)7syms x y a;x=solve('xA3+a*x+1=0','x')x=solve('sin(x)+2*cos(x)-sqrt(x)=0','x')x y=solve('log(x/y)=9','exp(x+y)=3','x','y')8syms n;x,y=dsolve('x*(D2y)+(1-n)*(Dy)+y=0','y(0)=0','Dy(0)=0','x')思考练习2syms x B1 B2 a bs1=2*(cos(x)A2)-(sin(x)A2;s2=sin(B1)*cos(B2)-cos(B1)*sin(B2);s3=sqrt(a+sqrt(aA2-b)/2)+sqrt(a-sqrt(aA2-b)/2);s4=(4