{VERSION 3 0 "IBM INTEL NT" "3.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 }{CSTYLE "2D Math" -1 2 "Times" 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 }{CSTYLE "2D Comment" 2 18 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 } {CSTYLE "" -1 256 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }{CSTYLE "" -1 257 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 258 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 259 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 } {CSTYLE "" -1 260 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }{CSTYLE "" -1 261 "" 1 14 0 0 0 0 0 1 0 0 0 0 0 0 0 }{CSTYLE "" -1 262 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }{CSTYLE "" -1 263 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 } {CSTYLE "" -1 264 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 }{CSTYLE "" -1 265 "" 1 12 0 0 0 0 0 0 0 0 0 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Heading 1" 0 3 1 {CSTYLE "" -1 -1 "" 1 18 0 0 0 0 0 1 0 0 0 0 0 0 0 }1 0 0 0 8 4 0 0 0 0 0 0 -1 0 }{PSTYLE "Heading 2" 3 4 1 {CSTYLE "" -1 -1 "" 1 14 0 0 0 0 0 0 0 0 0 0 0 0 0 }0 0 0 -1 8 2 0 0 0 0 0 0 -1 0 }{PSTYLE "Title" 0 18 1 {CSTYLE "" -1 -1 "" 1 18 0 0 0 0 0 1 1 0 0 0 0 0 0 }3 0 0 -1 12 12 0 0 0 0 0 0 19 0 }{PSTYLE "Author" 0 19 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 0 0 -1 8 8 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 256 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 257 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 258 1 {CSTYLE "" -1 -1 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }} {SECT 0 {EXCHG {PARA 18 "" 0 "" {TEXT -1 41 "Maple Illustrations of It erated Integrals" }}{PARA 19 "" 0 "" {TEXT -1 13 "J. A. Ziegler" }} {PARA 256 "" 0 "" {TEXT -1 37 "Southern Polytechnic State University" }}{PARA 257 "" 0 "" {TEXT -1 17 "jziegler@spsu.edu" }}{PARA 258 "" 0 " " {TEXT 265 44 "http://www2.SPSU.edu/math/ziegler/index.html" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 349 "Abstract: A method is given for using M aple to illustrate the usual geometric interpretation of the evaluatio n of iterated double integrals in rectangular and sphereical coordinat es. This is suitable for student use, individually, or in a computer \+ laboratory setting. An elaboration of this method yields illustration s suitable for classroom use." }}{PARA 0 "" 0 "" {TEXT -1 1 " " }}} {SECT 1 {PARA 3 "" 0 "" {TEXT -1 35 "A Volume in Rectangular Coordinat es" }}{EXCHG {PARA 4 "" 0 "" {TEXT -1 23 "Sweeping Out the Volume" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 153 "A typical exercise in evaluating double integrals by using ite rated integrals is to find the volume enclosed between the graph of th e function f(x,y) = " }{XPPEDIT 18 0 "4-(x/2)^2-(y/3)^2;" "6#,(\"\"% \"\"\"*$*&%\"xGF%\"\"#!\"\"\"\"#F**$*&%\"yGF%\"\"$F*\"\"#F*" }{TEXT -1 68 " and the x,y-plane, over the region R enclosed by the curves x \+ = 0, " }}{PARA 0 "" 0 "" {TEXT -1 19 "y = x + 3, and y = " }{XPPEDIT 18 0 "x^2+1;" "6#,&*$%\"xG\"\"#\"\"\"\"\"\"F'" }{TEXT -1 51 ". Here R is \"y-simple.\" The \"lower curve\" is y = " }{XPPEDIT 18 0 "x^2+1; " "6#,&*$%\"xG\"\"#\"\"\"\"\"\"F'" }{TEXT -1 38 " and the \"upper curv e\" is y = x + 3. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 103 "The volum e between the surface z = f(x,y) and the x,y-plane over the region R i s given by the integral " }{XPPEDIT 18 0 "Int(Int(z,x = R .. ``),y = ` ` .. ``);" "6#-%$IntG6$-F$6$%\"zG/%\"xG;%\"RG%!G/%\"yG;F-F-" }{TEXT -1 51 ". Its value may be found via the iterated inegral " }{XPPEDIT 18 0 "int(int(4-(x/2)^2-(y/3)^2,y = x^2+1 .. x+3),x = 0 .. 2);" "6#-%$ intG6$-F$6$,(\"\"%\"\"\"*$*&%\"xGF*\"\"#!\"\"\"\"#F/*$*&%\"yGF*\"\"$F/ \"\"#F//F3;,&*$F-\"\"#F*\"\"\"F*,&F-F*\"\"$F*/F-;\"\"!\"\"#" }{TEXT -1 107 ". Maple can be used in the following way to help us visualize what is meant by \"sweeping out the volume\". " }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 36 "restart:with(plots):with(plottools):" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 114 "We begin by defining the function , f, and two functions whose graphs are the upper and lower curves, re spectively." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "f:=(x,y)->4- (x/2)^2-(y/3)^2:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 11 "Uc:=x-> x+3:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "Lc:=x->x^2+1:" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 100 "Next, we create the graphs of f o ver R and of the curves which bound R. We collect the latter as R." } }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 80 "s:=plot3d(f(x,y),x=0..2,y= Lc(x)..Uc(x),grid=[10,5],style=wireframe,color=black):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 49 "L1:=line([0,1,0],[0,3,0],color=blue ,thickness=2):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 72 "L2:=space curve(\{[x,Uc(x),0],[x,Lc(x),0]\},x=0..2,color=blue,thickness=2):" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 11 "R:=\{L1,L2\}:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 68 "display(s,R,view=[0..2,0..5,0..4],o rientation=[-23,56],axes=normal);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 161 "To help us to see the solid, we create the graphs of the lines jo ining the vertices of R with the corresponding points on the graph of \+ f. We collect these as C." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 55 "C1:=line([0,1,0],[0,1,f(0,1)],color=green,thickness=3):" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 55 "C2:=line([0,3,0],[0,3,f(0,3) ],color=green,thickness=3):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 55 "C3:=line([2,5,0],[2,5,f(2,5)],color=green,thickness=3):" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 14 "C:=\{C1,C2,C3\}:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 70 "display(s,R,C,view=[0..2,0..5,0..4] ,orientation=[-23,56],axes=normal);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 227 "Now we define, as an \"image-valued\" function, that portion o f the plane which \"sweeps out\" the volume as described by the \"oute r\" integration. The area of this portion of the plane is, of course, given by the \"inner\" integral." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 77 "A:=x->plot3d([x,y,z],y=Lc(x)..Uc(x),z=0..f(x,y),color =red,style=patchnogrid):" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 193 "We m ake a sequence of pictures showing the succesive positions of this \"c ross section\" together with the other graphs as background. It is im portant that the background appear in each \"frame.\"" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 51 "SV:=seq(display(A(0),A(i/20+0.001), s,C,R),i=0..40):" }{TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 152 "Finally, we display the result. To run the movie, we click on th e image and press the \"play\" button of the \"controls\" which appear below the toll bar. " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 83 "di splay(SV,insequence=true,axes=normal,view=[0..2,0..5,0..4],orientation =[-23,56]);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 4 "" 0 "" {TEXT -1 20 "Generating the Solid" }}}{EXCHG {PARA 0 " " 0 "" {TEXT -1 515 "A somewhat more elaborate procedure may be used t o \"generate the solid.\" This makes a good classroom demonstration, b ut is unnecessarily complicated for an introductory Maple laboratory. \+ This procedure is a good illustration of the use of \"image-valued\" M aple functions. (These are an invention of my own, although very like ly many others working with Maple have invented them, too.) The 0.001 in the functional arguments prevent the plotting commands from produc ing what would be essentially \"empty plot\" errors." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 87 "surf:=t->plot3d(f(x,y),x=0..t,y=Lc(x)..Uc (x),grid=[10,5],color=blue,style=patchnogrid):" }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 84 "Lside:=t->plot3d([x,Lc(x),z],x=0..t,z=0..f(x,L c(x)),color=yellow,style=patchnogrid):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 84 "Uside:=t->plot3d([x,Uc(x),z],x=0..t,z=0..f(x,Uc(x)),c olor=yellow,style=patchnogrid):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 73 "LLine:=t->line([t,Lc(t),0],[t,Lc(t),f(t,Lc(t))],color=black,th ickness=3):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 73 "ULine:=t->li ne([t,Uc(t),0],[t,Uc(t),f(t,Uc(t))],color=black,thickness=3):" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 64 "Bline:=t->line([t,Lc(t),0],[ t,Uc(t),0],color=black,thickness=3):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 159 "SV2:=seq(display(A(0),A(i/20+0.001),surf(i/20+0.001) ,Lside(i/20+0.001),Uside(i/20+0.001),LLine(i/20+0.001),ULine(i/20+0.00 1),Bline(i/20+0.001),s,C,R),i=0..40):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 84 "display(SV2,insequence=true,axes=normal,view=[0..2,0. .5,0..4],orientation=[-23,56]);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{SECT 1 {PARA 3 "" 0 "" {TEXT -1 33 "A Volume in Spherica l Coordinates" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 36 "restart:wit h(plots):with(plottools):" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 256 9 "Exer cise:" }{TEXT -1 48 " Draw the volume enclosed below by the cone z = \+ " }{XPPEDIT 18 0 "sqrt(x^2+y^2);" "6#-%%sqrtG6#,&*$%\"xG\"\"#\"\"\"*$% \"yG\"\"#F*" }{TEXT -1 33 " and above by the hemisphere z = " } {XPPEDIT 18 0 "sqrt(9-x^2-y^2);" "6#-%%sqrtG6#,(\"\"*\"\"\"*$%\"xG\"\" #!\"\"*$%\"yG\"\"#F," }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }{TEXT 260 9 "Solution:" }{TEXT -1 158 " Note that when y = 0 and x > \+ 0, the first equation reduces to z = x. Likewise, when x = 0 and y > \+ 0, z = y. Thinking in spherical coordinates, we see that " }{XPPEDIT 18 0 "phi = Pi/4;" "6#/%$phiG*&%#PiG\"\"\"\"\"%!\"\"" }{TEXT -1 116 " \+ at the wall of the cone. So the portion of the hemisphere we need may be drawn in the following way. By choosing " }{TEXT 257 18 "style = \+ wireframe," }{TEXT -1 71 " we will be able to see into the solid. It \+ is convenient to use t for " }{XPPEDIT 18 0 "theta;" "6#%&thetaG" } {TEXT -1 11 " and p for " }{XPPEDIT 18 0 "phi;" "6#%$phiG" }{TEXT -1 1 "," }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 78 "S:=plot3d(3,t=0..2* Pi,p=0..Pi/4,coords=spherical,style=wireframe,color=black):" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 115 "It is quite easy to draw the cone as a parametric surface in spherical coordinates. Along the wall o f the cone, " }{XPPEDIT 18 0 "phi = Pi/4;" "6#/%$phiG*&%#PiG\"\"\"\"\" %!\"\"" }{TEXT -1 10 " , while " }{XPPEDIT 18 0 "rho;" "6#%$rhoG" } {TEXT -1 22 " runs from 0 to 3 and " }{XPPEDIT 18 0 "theta;" "6#%&thet aG" }{TEXT -1 11 " from 0 to " }{XPPEDIT 18 0 "2*Pi;" "6#*&\"\"#\"\"\" %#PiGF%" }{TEXT -1 3 ". " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 88 "c:=plot3d([rho,t,Pi/4],rho=0..3,t=0..2*Pi,coords=spherical,style=w ireframe,color=black):" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 23 "Now dis play the result." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 54 "display (S,c,scaling=constrained,orientation=[-25,75]);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 121 "Even when fully magnified, there are just too many \+ grid lines. This can be improved by inserting the optional command \+ " }{TEXT 258 1 " " }{TEXT -1 72 "grid=[25,5] in the definition of S \+ and grid=[5,25] to that of c. Thus" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 90 "S:=plot3d(3,t=0..2*Pi,p=0..Pi/4,coords=spherical,styl e=wireframe,color=black,grid=[25,5]):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 100 "c:=plot3d([rho,t,Pi/4],rho=0..3,t=0..2*Pi,coords=sph erical,style=wireframe,color=black,grid=[5,25]):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 54 "display(S,c,scaling=constrained,orientation=[ -25,75]);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 20 "That is much better. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }{TEXT 261 69 "Finding the v olume using iterated integrals in spherical coordinates." }}}{EXCHG {PARA 0 "" 0 "" {TEXT 262 48 "Visualization of a possible order of int egration" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 55 "Let us add a represen tative radius line to our picture." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 72 "R:=spacecurve([r,0,Pi/6],r=0..3,coords=spherical,colo r=red,thickness=3):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 56 "disp lay(S,c,R,scaling=constrained,orientation=[-25,75]);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 37 "It is clear that, inside our volume, " } {XPPEDIT 18 0 "rho;" "6#%$rhoG" }{TEXT -1 39 " may run from 0 to 3, in dependently of " }{XPPEDIT 18 0 "theta;" "6#%&thetaG" }{TEXT -1 5 " an d " }{XPPEDIT 18 0 "phi;" "6#%$phiG" }{TEXT -1 8 ", while " }{XPPEDIT 18 0 "phi;" "6#%$phiG" }{TEXT -1 16 " runs from 0 to " }{XPPEDIT 18 0 "pi/4;" "6#*&%#piG\"\"\"\"\"%!\"\"" }{TEXT -1 20 " , independently of \+ " }{XPPEDIT 18 0 "theta;" "6#%&thetaG" }{TEXT -1 93 ". Having realize d this, we can now write the necessary integrals. Integrating in the \+ order " }{XPPEDIT 18 0 "rho,phi,theta;" "6%%$rhoG%$phiG%&thetaG" } {TEXT -1 53 ", and remembering that in spherical coordinates dV = " } {XPPEDIT 18 0 "rho^2;" "6#*$%$rhoG\"\"#" }{XPPEDIT 18 0 "sin(phi);" "6 #-%$sinG6#%$phiG" }{XPPEDIT 18 0 "d*rho;" "6#*&%\"dG\"\"\"%$rhoGF%" } {TEXT -1 1 " " }{XPPEDIT 18 0 "d*phi;" "6#*&%\"dG\"\"\"%$phiGF%" } {TEXT -1 1 " " }{XPPEDIT 18 0 "d*theta;" "6#*&%\"dG\"\"\"%&thetaGF%" } {TEXT -1 10 ", we have " }{XPPEDIT 18 0 "Int(Int(Int(rho^2*sin(phi),rh o = 0 .. 3),phi = 0 .. Pi/4),theta = 0 .. 2*Pi);" "6#-%$IntG6$-F$6$-F$ 6$*&%$rhoG\"\"#-%$sinG6#%$phiG\"\"\"/F+;\"\"!\"\"$/F0;F4*&%#PiGF1\"\"% !\"\"/%&thetaG;F4*&\"\"#F1F9F1" }{TEXT -1 1 "." }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 68 "V:=Int(Int(Int(rho^2*sin(phi),rho=0..3),phi=0. .Pi/4),theta=0..2*Pi);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 9 "va lue(V);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "simplify(%);" }} }{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }{TEXT 263 39 "Illustrating the \+ process of integration" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 26 "The fir st integration, of " }{XPPEDIT 18 0 "rho;" "6#%$rhoG" }{TEXT -1 27 " f rom 0 to 3 while holding " }{XPPEDIT 18 0 "phi;" "6#%$phiG" }{TEXT -1 5 " and " }{XPPEDIT 18 0 "theta;" "6#%&thetaG" }{TEXT -1 84 " fixed, p roduces the line segment we have already seen. The second integration , of " }{XPPEDIT 18 0 "phi;" "6#%$phiG" }{TEXT -1 11 " from 0 to " } {XPPEDIT 18 0 "Pi/4;" "6#*&%#PiG\"\"\"\"\"%!\"\"" }{TEXT -1 15 " while holding " }{XPPEDIT 18 0 "theta;" "6#%&thetaG" }{TEXT -1 220 " fixed \+ produces a wedge-shaped surface. We may show this surface by using th e following parametric surface, which we define as a function of s in \+ a way that will be useful in a moment. Again, we abbreviate \"phi\" b y p. " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 100 "s1:=s->plot3d([rh o,2*Pi*s/60,p],rho=0..3,p=0..Pi/4,coords=spherical,color=red,style=pat chcontour): " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 60 "display(S, c,s1(0),scaling=constrained,orientation=[-25,75]);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 122 "Now we make use of our \"image-valued\" function , s1, to make an animation showing the surface \"sweeping out\" the vo lume as " }{XPPEDIT 18 0 "theta;" "6#%&thetaG" }{TEXT -1 16 " runs fro m 0 to " }{XPPEDIT 18 0 "2*Pi;" "6#*&\"\"#\"\"\"%#PiGF%" }{TEXT -1 80 ". Change the magnification to its maximum setting before running the animation." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 37 "pic:=seq(dis play(S,c,s1(t)),t=0..59):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 70 "display(pic,insequence=true,scaling=constrained,orientation=[-25,7 5]);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }{TEXT 264 53 "A more el aborate illustration of the last integration" }}}{EXCHG {PARA 0 "" 0 " " {TEXT -1 201 "By redefining the top and bottom surfaces as \"image-v alued\" functions, we may make an animation that really generates the \+ volume. The arguments \"s + 0.001\" in the functions sa and ca are us ed to keep " }{TEXT 259 6 "plot3d" }{TEXT -1 157 " from generating an \+ error when s = 0. The line, L, has been added to improve visibility. \+ Again, set the maximum magnification before running the animation." } }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 89 "sa:=s->plot3d(3,t=0..2*Pi* s/60,p=0..Pi/4,coords=spherical,style=patchnogrid,color=green):" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 98 "ca:=s->plot3d([rho,t,Pi/4],r ho=0..3,t=0..2*Pi*s/60,coords=spherical,style=patchnogrid,color=blue): " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 48 "L:=line([0,0,0],[0,0,3] ,color=navy,thickness=4):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 70 "pic1:=seq(display(L,S,c,s1(0),s1(s),sa(s+0.001),ca(s+0.001)),s=0.. 60):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 71 "display(pic1,insequ ence=true,scaling=constrained,orientation=[-25,75]);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}}{MARK "2 0 0" 35 }{VIEWOPTS 1 1 0 1 1 1803 }