Matlab-程序设计教程(第二版)刘卫国-课后参考答案.doc

第二章1 求下列表达式的值。（1）w=sqrt(2)*(1+0.34245*10(-6)(2)a=3.5;b=5;c=-9.8;x=(2*pi*a+(b+c)/(pi+a*b*c)-exp(2)/tan(b+c)+a(3)a=3.32;b=-7.9;y=2*pi*a(2)*(1-pi/4)*b-(0.8333-pi/4)*a(4)t=2,1-3*i;5,-0.65;z=1/2*exp(2*t)*log(t+sqrt(1+t(2)2 求下列表达式A=-1,5,-4;0,7,8;3,61,7;B=8,3,-1;2,5,3;-3,2,0;(1)A+6*B A2-B+eye(2)A*B A.*B B.*A(3)A/B BA(4)A,B A(1,3,:);B23 根据已知，完成下列操作（1）A=23,10,-0.778,0;41,-45,65,5;32,5,0,32;6,-9.54,54,3.14;K=find(A10&A25);A(K)（2）A=23,10,-0.778,0;41,-45,65,5;32,5,0,32;6,-9.54,54,3.14;B=A(1:3,:) C=A(:,1:2) D=A(2:4,3:4) E=B*C（3）E=90&score=80&score=70&score=60&score=69; disp(D);elseif score=0; disp(E);else disp(出错);end用switch语句score=input(请输入成绩:);switch fix(score/10) case 9,10 disp(A); case 8 disp(B); case 7 disp(C); case 6 disp(D); case 0,1,2,3,4,5 disp(E); otherwise disp(出错); end第四章1题1) X=0:10;Y=x-x.3/6;Plot(x,y)2) t=0:0.01:2*pi;x=8.*cos(t);y=4*sqrt(2).*sin(t);plot(x,y)2题M文件：t=-pi:pi/10:pi;y=1./(1+exp(-t);subplot(2,2,1);bar(t,y,b);title(bar(t,y,b);axis(-5,5,-3,3);subplot(2,2,2);stairs(t,y,k);title(stairs (t,y,k);axis(-5,5,-3,3);subplot(2,2,3);stem(t,y,m);title(stem (t,y,m);axis(-5,5,-3,3);subplot(2,2,4);loglog(t,y,g);title(loglog(t,y,g);axis(-5,5,-3,3);3题1） t=0:pi/100:2*pi;y=5*cos(t)+4;polar(t,y,-*)2） t=-pi/3:pi/100:pi/3;r=5*sin(t).2./cos(t); polar(t,r,-*)4题1)t=0:pi/100:2*pi;x=exp(-t/20).*cos(t);y=exp(-t/20).*sin(t);z=t;plot3(x,y,z)第五章：1题A=randn(10,5)1) X=mean(A)Y=std(A,0,1)2) max(max(A)min(min(A)3) B=sum(A,2)sum(B)4) sort(A);sort(A,2,descend)2题1） t=0:15:90;x1=0,0.2588,0.5000,0.7071,0.8660,0.9659,1.0000;a1=0:1:90;y1=interp1(t,x1,a1,spline)x2=0,0.2679,0.5774,1.0000,1.7320,3.7320,NaN;a2=0:1:75;y2= interp1(t,x2,a2,spline)p1=polyfit(t,x1,5);z1=polyval(p1,a1)p2=polyfit(t,x2,5);z2=polyval(p2,a2)4题P=2,-3,5,13;Q=1,5,8;p=polyder(P)p1=polyder(P,Q)p,q= polyder(P,Q)5题P1=1,2,4,0,5;P2=1,0;P3=1,2,3;1) P4=conv(P2,P3)P4=0,1,2,3,0;P=P1+P42) x=roots(P)3) A=-1,1.2,-1.4;0.75,2,3.5;0,5,2.5;Y=polyval(P,A)4) Z=polyvalm(P,A)第8章1.分解因式. (2)factor(sym(5135)(1)syms A x y;A=x4-y4;factor(A)2.求函数的极限（1）syms x; （2）syms x;limit(x-2)/(x2-4),x,2) f=(sqrt(pi)-sqrt(acos(x)/sqrt(x+1); limit(f,x,-1,right)3.求函数的符号导数。 （1）syms x y （2）sym x; f=sin(1/x); f=(1-cos(2*x)/x; diff(f) diff(f,x,2) diff(f) diff(f,x,2)4.求积分（1）x=sym(x) (2)sym(y) f=sqrt(exp(x)+1) f=x/(x+y) int(f) int(f) (3) (4) f=exp(x).*(1+exp(x)2; f=x .*log(x) int(f,0,log(2) int(f,1,exp(1) 5.求下列级数之和syms n;s=symsum(-1)(n+1)/n,1,inf)x=sym(x);syms n;s=symsum(x(2*n-1)/(2*n-1),x,inf)6.求函数在x=x.处的泰勒展开式 (1)sym