Task 11：习题

5-1

5-2

5-3

5-4

5-5

5-6

5-7

5-1

>> ezplot('sin(x).^2/(1+x.^2)-y') >> axis([-4,4,-1,1]),grid on

5-2

>> x=[0 1200];v=100;g=9.8; >> a1=pi/6;a2=pi/4;a3=pi*3/4; >> y=(x.*tan(a1)-g.*x.^2)/(2*v^2*cos(a1)^2); >> y2=(x.*tan(a2)-g.*x.^2)/(2*v^2*cos(a2)^2); >> y3=(x.*tan(a3)-g.*x.^2)/(2*v^2*cos(a3)^2); >> plot(x,y,'-',x,y2,'*',x,y3,':')

5-3

直角坐标：

>> x=0:pi/50:2*pi; >> r=-cos(2.*x).*sec(x); >> plot(x,r)

极坐标：

>> x=0:pi/50:2*pi; >> r=-cos(2.*x).*sec(x); >> [theta,rho]=cart2pol(x,r) theta = 1 至 13 列 -1.5708 -1.5077 -1.4428 -1.3742 -1.2998 -1.2170 -1.1226 -1.0127 -0.8828 -0.7282 -0.5462 -0.3383 -0.1137 14 至 26 列 0.1118 0.3225 0.5088 0.6689 0.8056 0.9238 1.0283 1.1233 1.2125 1.2991 1.3859 1.4756 -1.5708 27 至 39 列 -1.4678 -1.3547 -1.2301 -1.0936 -0.9468 -0.7937 -0.6400 -0.4924 -0.3561 -0.2347 -0.1292 -0.0394 0.0361 40 至 52 列 0.0989 0.1508 0.1933 0.2277 0.2551 0.2763 0.2922 0.3034 0.3102 0.3131 0.3123 0.3082 0.3008 53 至 65 列 0.2904 0.2769 0.2606 0.2414 0.2192 0.1942 0.1662 0.1352 0.1010 0.0634 0.0221 -0.0232 -0.0730 66 至 78 列 -0.1280 -0.1893 -0.2583 -0.3370 -0.4285 -0.5369 -0.6685 -0.8315 -1.0352 -1.2846 -1.5708 1.2773 1.0115 79 至 91 列 0.7916 0.6173 0.4802 0.3711 0.2828 0.2101 0.1494 0.0981 0.0543 0.0168 -0.0156 -0.0435 -0.0674 92 至 101 列 -0.0880 -0.1054 -0.1200 -0.1320 -0.1416 -0.1489 -0.1541 -0.1572 -0.1585 -0.1578 rho = 1.0e+15 * 1 至 13 列 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 14 至 26 列 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 6.2184 27 至 39 列 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 40 至 52 列 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 53 至 65 列 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 66 至 78 列 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 5.4437 0.0000 0.0000 79 至 91 列 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 92 至 101 列 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 >> set(h,'linewidth',3)

5-4

>> phi=pi/2:4*pi/5:4*pi; >> B=exp(i*phi); >> x1=real(B); >> y1=imag(B); >> subplot(1,2,2) >> fill(x1,y1,'g') >> axis square >> title('五角星') >> hold on >> ezplot('x.^2+y.^2-1') >> axis([-1,1,-1,1])

5-5

>> Y=magic(5) Y = 17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9 >> subplot(1,2,1) >> bar(Y)

5-6

>> x=[2200 1500 600 200 300 700] x = 1 至 4 列 2200 1500 600 200 5 至 6 列 300 700 >> pie(x,[1,0,0,0,0,0])

5-7

>> t=(0:20)/20;r=2.5-cos(2*pi*t); >> [x,y,z]=cylinder(r,40); >> fc=get(gca,'color'); >> h=surface(x,y,z,'FaceColor',fc,'EdgeColor','flat','FaceLighting', 'none','EdgeLighting','flat'); >> view(3); >> grid on >> axis off