数学建模作图.docx

1、数学建模作图x=linspace(0,4,10);y=2*x.3-9*x.2+12*x-3;plot(x,y)saveas(gcf,zuotu1.jpg)x=linspace(0,8,10);y=(x.2).(1/3);plot(x,y)saveas(gcf,zuotu2.jpg)function y=f1(x)if x0 y=2*x-1;elseif x)legend(y1,y2)x=linspace(0,1,30);y=sqrt(x);x.2fill(x,y,y)saveas(gcf,zuotu7.jpg)ezplot(x.2)/16+(y.2)/7-1,-5 5)hold onx=lin

2、space(-5,5,20)y=(2/3)*x.(3/2)-(x.3)/3;plot(x,y,-ko)gtext(相交点1)gtext(相交点2)legend(y1,y2)saveas(gcf,zuotu8.jpg)2.在同一页面上画出四幅下列图像（并且要详细标注，样式如右边）clearclcsubplot(2,2,1)ezplot(x.(2/3)+y.(2/3)-2.(2/3),-5 5)subplot(2,2,2)ezplot(x.2+y.2+2*x-2*sqrt(x.2+y.2),-5 5)subplot(2,2,3)ezplot(x.2+y.2).2-2*(x.2-y.2),-5 5)

3、subplot(2,2,4)ezplot(x.2+y.2).2-4*x*y,-5 5)saveas(gcf,zuotu9.jpg)2. 画出下列曲线并分别进行标注（1）输入命令：ezplot(3*t)/(1+t.2),(3*t.2)/(1+t.2),-18,18)（2）输入命令：ezplot(log(1+t.2) ,t-atan(t),-2,2)（3）输入命令：ezplot(1-t.2,t-t.3 ,-2,2)4.画出下图，并将其极值点及其拐点标出，同时画出过拐点的切线，及其过极值点的法线clearclfsyms tx=linspace(-2,2.5, 100);y=x.3-x.2-x+1;g

4、rid onplot(x,y)legend(y=x.3-x.2-x+1)hold onplot(-(1/3),32/27,ro)plot(1,0,ro)plot(1/3,16/27,bo)arrow(0 -4,0 8)arrow(-4 0,6 0)x0,y0=ginput(1)plot(x0,y0,b*)gtext(拐点切线)gtext(x轴)gtext(y轴)x1=-1/3 -1/3;y1=-10 10;x2=1, 1;y2=-10 10;plot(x1,y1,-k,x2,y2,-k)z=diff(t.3-t.2-t+1); z1=subs(z,t,1/3);x3=-2/3,4/3;y3=z

5、1*(x3-1/3)+16/27;plot(x3,y3,-k)hold onx4=1/3,1/3;y4=0 16/27;x5=0,1/3;y5=16/27 16/27;plot(x4,y4,-r,x5,y5,-r)axis offhold offsaveas(gcf,zuotu13.jpg)clearclfsyms tezplot(1+36*x/(x+3).2,-40,40)hold onplot(3,4,ro)plot(6,11/3,bo)arrow(0 -5,0 5)arrow(-50 0,50 0)x1,y1=ginput(1)plot(x1,y1,b*)gtext(拐点切线)gtext

6、(x轴)gtext(y轴)x2=3 3;y2=-10 10;plot(x2,y2,-k)z=diff(1+36*t/(t+3)2) z1=subs(z,t,6);x3=-4,16;y3=z1*(x3-6)+11/3;plot(x3,y3,-k)hold onx4=6,6;y4=0 11/3;x5=0,6;y5=11/3 11/3;plot(x4,y4,-r,x5,y5,-r)axis offhold offsaveas(gcf,zuotu14.jpg)5.设法用matlab画出下列图形圆的参数方程以及椭圆的参数方程如下：ezplot(5*cos(t),5*sin(t),-pi,pi)hold

7、onx1=-3 3;y1=4 4;x2=-3 3;y2=-4 -4;plot(x1,y1,-k,x2,y2,-k)hold onx3=3 3;y3=4 -4;x4=-3 -3;y4=4 -4;plot(x3,y3,-k,x4,y4,-k)hold onx5=-3 3;y5=4 -4;plot(x5,y5,-k)axis(-5 5 -5 5)axis offsaveas(gcf,zuotu15.jpg)ezplot(5*cos(t),5*sin(t)+2,-pi,pi)hold onezplot(2*cos(t),2*sin(t)+2,-pi,pi)hold onezplot(5*cos(t),

8、2*sin(t)+2,-pi,pi)arrow(0 -8,0 8)arrow(-8 0,8 0)axis off saveas(gcf,zuotu16.jpg)ezplot(5*cos(t),5*sin(t),-pi,pi)hold onx1=-5*sin(2*pi/5),0;y1=5* sin(pi/10),5;x2=0,5*sin(2*pi/5);y2=5,5* sin(pi/10);plot(x1,y1,x2,y2)x3=-5*sin(pi/5),5*sin(pi/5);y3=-5*cos(pi/5),-5*cos(pi/5);x4=-5*sin(2*pi/5),-5*sin(pi/5);y4=5* sin(pi/10),-5*cos(pi/5);x5=5*sin(pi/5),5*sin(2*pi/5);y5=-5*cos(pi/5),5* sin(pi/10);plot(x3,y3,x4,y4,x5,y5)x=x1,x2,x3,x4,x5;y=y1,y2,y3,y4,y5;fill(x,y,-)axis offsaveas(gcf,zuotu17.jpg)