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);switchncasenum2cell(90:100)p=A;casenum2cell(80:89)p=B;casenum2cell(70:79)p=C;casenum2cell(60:69)p=D;otherwisep=E;endprice=p(2)n=input(请输入成绩);ifn=90&n=80&n=70&n=60&naa=n(m

2、);elseifn(m)bb=n(m);endendmax=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=-3.0:0.1:3.0;forn=1:61a=b(n);y(n)=(exp(0.3*a)-exp(-0.3*a)/2*sin(a+0.3)+log(0.3+a)/2);endy5y1=0;y2=1;n=input(请输入n的值：);fori=1:ny仁y1+1/i八2;y2=y2*(4*i*i)/(2*i-1)*(2*i+1);endy1y26A=1,1,1,1,1,1

3、;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:);ifn=0disp(A(n,:);elseifn0disp(lasterr);elsedisp(A(6,:);disp(lasterr);end7(1)f=;forn=1:40f(n)=n+10*log(n2+5);endy=f(40)/(f(30)+f(20)(2)f=;a=0;forn=1:40f(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=inpu

4、t(输入n值：);fori=1:ny=y+iAm;endy*functions=shi8_1(n,m)s=0;fori=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./N1./N.A23s=fix(100*rand(1,20)*9/10+10)y=sum(s)/20j=0;fori=1:20ifs(i)y&rem(s(i),2)=0j=j+1;A(j)=s(i);elsecontinue;endendA4y1=0;y2=0;n=input(请输入n的值：);fori=1:ny

5、仁y1+-(-1)Ai/(2*i-1);y2=y2+1/4八i;endy1y2unit4实验指导1(1)x=-10:0.05:10;y=x-x.A3./6;plot(x,y)(2)x=-10:0.5:10;ezplot(xA2+2*yA2-64,-8,8);gridon;2t=-pi:pi/10:pi;y=1./(1+exp(-t);subplot(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);

6、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);3(1)t=0:pi/50:2*pi;r=5.*cos(t)+4;polar(t,r);title(rho=5*costheta+4);(2)t=-pi/3:pi/50:pi/3;r=5.*(sin(t).八2)./cos(t);polar(t,r);4(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);grido

7、n;(2)x,y=meshgrid(-5:5);z=zeros(11)+5;mesh(x,y,z);shadinginterp;5x,y,z=sphere(20);surf(x,y,z);axisoff;shadinginterp;m=moviein(20);fori=1:20axis(-i,i,-i,i,-i,i)m(:,i)=getframe;endmovie(m,4);思考练习2(1)x=-5:0.1:5;y=(1./(2*pi).*exp(-(x.A2)/2);plot(x,y);(2)t=-2*pi:0.1:2*pi;x=t.*sin(t);y=t.*cos(t);plot(x,y)

8、;gridon;3t=0:pi/1000:pi;x=sin(3.*t).*cos(t);y1=sin(3.*t).*sin(t);y2=2.*x-0.5;plot(x,y1,k,x,y2);holdon;k=find(abs(y1-y2)0.5)n=n+1;endendny=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,1,1)zong=sum(p,2);Max,wei=max(zong)Min,wei=min(zong)zcj,xs

9、xh=sort(zong,descend)6x=1:10:101;y=0,1.0414,1.3222,1.4914,1.6128,1.7076,1.7853,1.8513,1.9085,1.9590,2.0043;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1A=1/2,1/3,1/4;1/3,1/4,1/5;1/4,1/5,1/6;p=0.95,0.67,0.52;x=ApA二1/2,1/3,1/4;1/3,1/4,1/5：1/4：1/5,1/6;p=0.95,0.67,0.53;x=Apc

10、ond(A)2(1)x1=fzero(funx1,-1)functionfx=funx1(x)fx=xA41+xA3+1;(2)x2=fzero(funx2,0.5)/unctionfx=funx2(x)fx=x-sin(x)/x;(3)options=optimset(Display,off);x=fsolve(fun3,1,1,1,options)q=fun3(x)functionq=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)t0=0;tf=5;y0=1;

11、t,y=ode23(fun4,t0,tf,y0);tyunctionyp=fun4(t,y)yp=-(1.2+sin(1O*t)*y;(2)t0=0;tf=5;y0=1;t,y=ode23(fun5,t0,tf,y0);tyfunctionyp=fun5(t,y)yp=cos(t)-y/(1+t八2);4x=fminbnd(mymin,0,2);-mymin(x)functionfx=mymin(X)fx=-(1+x.A2)/(1+x.A4);5options=optimset(Display,off);x,fval=fmineon(fun6,0,0,0,a,b,lb,ub)-fvalfunc

12、tionf=fun6(x)f=-(sqrt(x(1)+(400-x(1)*1.1+(sqrt(x(2)+(400-x(1)*1.1-x(2)*1.1+sqrt(3)+(400-x(1)*1.1-x(2)*1.1-x(3)*1.1+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)(2)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(LB)2 (1)x1=fzero(

13、funx1,1.5)functionfx=funx1(x)fx=3*x+sin(x)-exp(x);MiS|MiHi(2)x仁fzero(funx2,1)functionfx=funx2(x)fx=x-1/x+5;(3).oRtionsFoptimseMPisppyToff);x=fsolve(fun3,3,0,options)q=fun3(x)functionq=fun3(p)x=p(1)；IIHIIIIIIIIIIIIIIIIHIIIIIIHIHIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIBIy=p(2)；q(1)=x八2+y八2-9;q(2)=x+y-1;(1)

14、tO=O;tf=5;yo=o,i;t,y=ode45(vdpol,t0,tf,y0);t,yfunctionydot=vdpol(t,y);ydot(1)=(2-3*y(2)-2*t*y(1)./(1+tA2);ydot(2)=y(1);ydot=ydot;(2)t0=0;tf=5;y0=i；o；2；t,y=ode45(vdpoll,t0,tf,y0);I(I*t，yi!ibiiaiooiaimomimiuiI八functionydot=vdpoll(t,y);ydot(1)=cos(t)-y(3)./(3+sin(t)+5*y(1).*cos(2*t)/(t+1).A2)-y(2);ydot

15、(2)=y(1);ydot(3)=y(2);ydot=ydot;4x=fminbnd(mymin,0,pi);-mymin(x)functionfx=mymin(x)fx=-sin(x)-cos(x.A2);5x,y1=fminbnd(mymax,0,1.5);-yifunctionfx=mymax(x);fx=-(9*x+4*x.A3-12*x.A2);unit7实验指导l11*1(11)II*Iiri*i11III*IfI/itIr*ftformatlongfx=inline(sin(x)./x);I,n=quadl(fx,0,2,1e-10)(2)formatlongfx=inline(

16、1./(x-0.3)八2+0.01)-1./(x-0.9)八2+0.04)-6);I,n=quad(fx,0,1,1e-10)2(1)globalki;ki=0;I=dblquad(fxy,0,1,0,1)ki(2)f=inline(abs(cos(x+y),x,y);I=dblquad(f,0,pi,0,pi)3X=0.3:0.2:1.5;F=0.3895,0.6598,0.9147,1.1611,1.3971,1.6212,1.8325;trapz(X,F)4p=0:pi/5:2*pi;forn=1:3nDX=diff(sin(p),n)end5f=inline(sin(x)./(x+co

17、s(2.*x);g=inline(cos(x).*(x+cos(2*x)-sin(x).*(1-2.*sin(2*x)/(x+cos(2.*x).八2);x=-pi:0.01:pi;p=polyfit(x,f(x),5);dp=polyder(p);dpx=polyval(dp,x);dx=diff(f(x,3.01)/0.01;gx=g(x);plot(x,dpx,x,dx,.,x,gx,-);%求dp在假设点的函数值%直接对f(x)求数值导数%求函数f的导函数g在假设点的导数%作图思考练习2formatlongfx=inline(1./(1+x八2);I,n=quad(fx,-Inf,In

18、f,1e-10)I,n=quadl(fx,-Inf,Inf,1e-10)x=-100000:100000;y=1./(1+x.A2);trapz(x,y)formatshort3(1)formatlongfx=inline(log(1+x)./(1+x.A2);I,n=quad(fx,0,1,1e-10)(2)formatlongfx=inline(sqrt(cos(t42)+4*sin(2*t).八2)+1);I,n=quad(fx,0,2*pi,1e-10)4f=inline(4.*x.*z.*exp(-z.八2.*y-x.八2);I=triplequad(f,0,pi,0,pi,0,1)

19、5 f=inline(sin(x);g=inline(cos(x);x=0:0.01:2*pi;p=polyfit(x,f(x),5);dp=polyder(p);dpx=polyval(dp,x);dx=diff(f(x,2*pi+0.01)/0.01;gx=g(x);plot(x,dpx,x,dx,.,x,gx,-)unit8实验指导1symsxy;s=xA4-yA4;factor(s)factor(5135)2symsx;f=(x-2)/(xA2-4);limit(f,x,2)symx;f=(sqrt(pi)-sqrt(acos(x)/sqrt(x+1);limit(f,x,-1,rig

20、ht)3symx;f=sin(1/x);diff(f,x)diff(f,x,2)symx;f=(1-cos(2*x)/x;diff(f,x)diff(f,x,2)4symx;f=sqrt(exp(x)+1);int(f,x)symsxy;f=x/(x+y);int(f,y)symx;f=exp(x)*(1+exp(x)八2;int(f,x,0,log(2)symx;f=x*log(x);int(f,x,1,exp(1)5symx;s=symsum(-1)八(x+1)/x,1,lnf)symy;z=symsum(yA(2*y-1)/(2*y-1),1,Inf)6symx;f1=(exp(x)+e

21、xp(-x)/2;f2=sqrt(xA3-2*x+1);taylor(f1,x,5,0)taylor(f2,x,6,0)7symsxya;x=solve(xA3+a*x+1=0,x)x=solve(sin(x)+2*cos(x)-sqrt(x)=0,x)xy=solve(log(x/y)=9,exp(x+y)=3,x,y)8symsn;x,y=dsolve(x*(D2y)+(1-n)*(Dy)+y=0,y(0)=0,Dy(0)=0,x)思考练习2symsxB1B2abs1=2*(cos(x)八2)-(sin(x)八2;s2=sin(B1)*cos(B2)-cos(B1)*sin(B2);s3=sqrt(a+sqrt(aA2-b)/2)+sqrt(a-sqrt(aA2-b)/2);s4=(4*xA2+8*x+3)/(2*x+1);h1=simplify(s1)h2=s