{VERSION 5 0 "IBM INTEL NT" "5.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 1 }{CSTYLE "2D Math" -1 2 "Times" 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 1 }{CSTYLE "2D Comment" 2 18 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 256 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 257 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 258 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 259 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 260 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 261 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 262 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 263 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 264 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 265 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 266 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 267 "" 1 18 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 268 "" 1 14 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "T imes" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }1 1 0 0 0 0 1 0 1 0 2 2 0 1 } {PSTYLE "Heading 2" -1 4 1 {CSTYLE "" -1 -1 "Times" 1 14 0 0 0 1 2 1 2 2 2 2 1 1 1 1 }1 1 0 0 8 2 1 0 1 0 2 2 0 1 }{PSTYLE "Normal" -1 256 1 {CSTYLE "" -1 -1 "Times" 1 14 0 0 0 1 2 1 2 2 2 2 1 1 1 1 }1 1 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Normal" -1 257 1 {CSTYLE "" -1 -1 "Times " 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }3 1 0 0 0 0 1 0 1 0 2 2 0 1 }} {SECT 0 {EXCHG {PARA 257 "" 0 "" {TEXT -1 0 "" }{TEXT 266 0 "" }{TEXT 267 23 "Calculus IV with Maple\n" }{TEXT 268 32 "Copyright 2002, Dr. J ack Wagner\n" }{TEXT -1 30 "j.wagner@intelligentsearch.com" }}}{EXCHG {PARA 4 "" 0 "" {TEXT -1 0 "" }}{PARA 4 "" 0 "" {TEXT -1 60 "Lesson 11 : Volumes, Volume Integrals and Change of Variables" }}{PARA 0 "" 0 " " {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 156 "Somewhere arou nd the middle of the first year Calculus course we learn how to evalua te integrals by a \"change of variables\" technique. An integral such as " }{XPPEDIT 18 0 "Int(1/(1+x^2),x);" "6#-%$IntG6$*&\"\"\"F',&F'F'* $%\"xG\"\"#F'!\"\"F*" }{TEXT -1 37 " is transformed by the substitutio n, " }{XPPEDIT 18 0 "x = tan(u);" "6#/%\"xG-%$tanG6#%\"uG" }{TEXT -1 17 " to the integral " }{XPPEDIT 18 0 "Int(1,u);" "6#-%$IntG6$\"\"\"% \"uG" }{TEXT -1 33 ", from which we easily find that " }{XPPEDIT 18 0 "Int(1/(1+x^2),x) = arctan(x)+K;" "6#/-%$IntG6$*&\"\"\"F(,&F(F(*$%\"xG \"\"#F(!\"\"F+,&-%'arctanG6#F+F(%\"KGF(" }{TEXT -1 288 " . The same i dea may be applied to integrals in higher dimensions. We may regard t his procedure as a change of coordinates or as a reparametrization, wh ichever viewpoint is more convenient. Look at the problem of finding \+ the area of a circle from the perspective of surface integrals. " }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 12 "E xample 11.1" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 " " {TEXT -1 33 "We seek to evaluate the function " }{XPPEDIT 18 0 "F;" "6#%\"FG" }{TEXT -1 1 ":" }{XPPEDIT 18 0 "proc (x, y) options operator , arrow; 1 end;" "6#f*6$%\"xG%\"yG7\"6$%)operatorG%&arrowG6\"\"\"\"F+F +F+" }{TEXT -1 83 " , over the plane area of the circle, considered as a surface, with radius a, i.e. " }{XPPEDIT 18 0 "Int(1,A);" "6#-%$Int G6$\"\"\"%\"AG" }{TEXT -1 3 ". " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 63 "restart:with(plots): with(LinearAlgebra): with(Vector Calculus):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 23 "A := Int(Int( 1, x), y);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 49 "We reparameterize \+ the area in polar coordinates." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "S := ;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 35 "Now we know exactly how to proceed." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 29 "J := Jacobian(S, [r, theta]);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 31 "dA := simplify(Determinant(J));" }} }{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 44 "Area := Int(Int(dA, r=0..a) , theta=0..2*Pi);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "value( Area);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 447 "Now we extend this to higher dimensions. Actually, what we were doing in the case of areas was specializing the more general \+ technique to the two dimensional case. By taking the parallelogram as \+ the element of area, we were regarding area as the volume of a flat pa rallelopiped; or, if you will, the volume of a parallelopiped whose a \+ height is one and whose base is the area of the given parallelogram. \+ Just as the element of area was taken as " }{TEXT 257 5 "dA = " } {XPPEDIT 18 0 "sqrt(det(J[s]^T*J[s]));" "6#-%%sqrtG6#-%$detG6#*&)&%\"J G6#%\"sG%\"TG\"\"\"&F,6#F.F0" }{MPLTEXT 1 0 1 " " }{TEXT -1 4 "= ||" } {XPPEDIT 18 0 "J[s];" "6#&%\"JG6#%\"sG" }{TEXT -1 10 "||, where " } {XPPEDIT 18 0 "J[s];" "6#&%\"JG6#%\"sG" }{TEXT -1 60 " is the Jacobian of the parameterization of the surface, so " }{TEXT 258 3 "dV=" } {TEXT -1 2 "||" }{XPPEDIT 18 0 "J[v];" "6#&%\"JG6#%\"vG" }{TEXT -1 3 " ||=" }{XPPEDIT 18 0 "sqrt(det(J[v]^T*J[v]));" "6#-%%sqrtG6#-%$detG6#*& )&%\"JG6#%\"vG%\"TG\"\"\"&F,6#F.F0" }{TEXT -1 8 " where " }{XPPEDIT 18 0 "J[v];" "6#&%\"JG6#%\"vG" }{TEXT -1 49 " is the Jacobian of the \+ volume parameterization." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }} {PARA 0 "" 0 "" {TEXT 259 12 "Example 11.2" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 17 "For the sphere, " } {XPPEDIT 18 0 "x^2+y^2+z^2 = a^2;" "6#/,(*$%\"xG\"\"#\"\"\"*$%\"yGF'F( *$%\"zGF'F(*$%\"aGF'" }{TEXT -1 38 " , a convenient coordinate change is:" }}}{EXCHG {PARA 0 "" 0 "" {XPPEDIT 18 0 "x = r*cos(phi)*cos(thet a);" "6#/%\"xG*(%\"rG\"\"\"-%$cosG6#%$phiGF'-F)6#%&thetaGF'" }{TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {XPPEDIT 18 0 "y = r*cos(phi)*sin(th eta);" "6#/%\"yG*(%\"rG\"\"\"-%$cosG6#%$phiGF'-%$sinG6#%&thetaGF'" }}} {EXCHG {PARA 0 "" 0 "" {XPPEDIT 18 0 "z = r*sin(phi);" "6#/%\"zG*&%\"r G\"\"\"-%$sinG6#%$phiGF'" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 38 "This \+ is expressed in vector form as: [" }{XPPEDIT 18 0 "r*cos(phi)*cos(thet a);" "6#*(%\"rG\"\"\"-%$cosG6#%$phiGF%-F'6#%&thetaGF%" }{TEXT -1 2 ", \+ " }{XPPEDIT 18 0 "r*cos(phi)*sin(theta);" "6#*(%\"rG\"\"\"-%$cosG6#%$p hiGF%-%$sinG6#%&thetaGF%" }{TEXT -1 2 ", " }{XPPEDIT 18 0 "r*sin(phi); " "6#*&%\"rG\"\"\"-%$sinG6#%$phiGF%" }{TEXT -1 1 "]" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 51 "restart: with(LinearAlgebra): with(Vector Calculus):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 64 "S := ;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "J := Jacobian(S, [r, theta, phi]);" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 60 "v := simplify(sqrt(Determina nt(Transpose(J).J)), symbolic); " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 62 "V := Int(Int(Int(v, r=0..a), theta=0..2*Pi), phi=-Pi/ 2..Pi/2);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 9 "value(V);" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 170 "Fortunately, in practice, most of the volumes and surfaces we have to deal with have convenient and sym metrical, parameterizations. In general, the volume of a solid is:" } }}{EXCHG {PARA 0 "" 0 "" {XPPEDIT 18 0 "V = Int(Int(Int(` `,x),y),z); " "6#/%\"VG-%$IntG6$-F&6$-F&6$%\"~G%\"xG%\"yG%\"zG" }{TEXT -1 3 " = " }{XPPEDIT 18 0 "Int(Int(Int(`||f'(u,v,w)||`,u),v),w);" "6#-%$IntG6$-F$ 6$-F$6$%.|gr|grf'(u,v,w)|gr|grG%\"uG%\"vG%\"wG" }{TEXT -1 9 " , where \+ " }{TEXT 260 1 "f" }{TEXT -1 2 ": " }{XPPEDIT 18 0 "proc (U) options o perator, arrow; V end;" "6#f*6#%\"UG7\"6$%)operatorG%&arrowG6\"%\"VGF* F*F*" }{TEXT -1 31 " is the reparametrization map. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 637 " Looked at in this way, the computatio n of volume is nothing more than the computation of the reparameteriza tion of the Cartesian coordinate volume element, transformed into new \+ coordinates representing the solid in question, between appropriate li mits. Looked at from the opposite perspective, reparameterization dis torts volume by a factor equal to the determinant of the Jacobian matr ix; that is, by a factor equal to the ratio of the volume of a transfo rmed parallelepiped to an original parallelepiped. Volume, of course, is meant in the most general sense and is intended to include area an d arc length as special cases. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 261 12 "Example 11.3" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 383 "Consider an elli pse in the plane x=5 with its center at (5, 0, 0), semi-major axis of \+ 4 in the z direction and semi-minor axis of 2 in the x direction. Rot ate this about the z axis through an ellipse in the x-y plane with sem i-major axis 10 in the y direction and semi-minor axis 5 in the x dire ction. What is the volume of the resulting solid?\n\011This figure may be parameterized by " }}}{EXCHG {PARA 0 "" 0 "" {XPPEDIT 18 0 "[(5+2* s*cos(theta))*cos(phi), 10+2*s*cos(theta)*sin(phi), 4*s*sin(theta)];" "6#7%*&,&\"\"&\"\"\"*(\"\"#F'%\"sGF'-%$cosG6#%&thetaGF'F'F'-F,6#%$phiG F',&\"#5F'**F)F'F*F'-F,6#F.F'-%$sinG6#F1F'F'*(\"\"%F'F*F'-F86#F.F'" } {TEXT -1 13 " , s = 0..1, " }{XPPEDIT 18 0 "theta;" "6#%&thetaG" } {TEXT -1 6 " = 0.." }{XPPEDIT 18 0 "2*Pi;" "6#*&\"\"#\"\"\"%#PiGF%" } {TEXT -1 2 ", " }{XPPEDIT 18 0 "phi;" "6#%$phiG" }{TEXT -1 6 " = 0.." }{XPPEDIT 18 0 "2*Pi;" "6#*&\"\"#\"\"\"%#PiGF%" }{TEXT -1 1 " " }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 174 " It is an elliptical dough nut with an elliptical cross section. Note that we are plotting only \+ the surface, so we leave out the s parameter which provides the volume ." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 63 "restart: with(plots): \+ with(LinearAlgebra):with(VectorCalculus):" }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 75 "t := <(5+2*cos(theta))*cos(phi), (10+2*cos(theta))* sin(phi), 4*sin(theta)>;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 102 "plot3d(t, theta=0..2*Pi, phi=0..2*Pi, axes=normal, scaling=constr ained, color=blue, style=\nwireframe);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 90 "Now we calculate. We must include the s parameter since \+ we are now concerned with volume." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 82 "T := <(5+2*s*cos(theta))*cos(phi), (10+2*s*cos(theta) )*sin(phi), 4*s*sin(theta)>;\011" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "J := Jacobian(T, [theta, phi, s]);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 60 "dV := sqrt(simplify(Determinant(Transpose (J).J)), symbolic);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 64 "Volu me := int(int(int(dV, theta=0..2*Pi), phi=0..2*Pi), s=0..1);" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 238 "The functions commonly integrated over volumes are densities or changes in density that vary from point to point in the volume. The result is then the entire quantity or th e net change in density of the physical parameter being studied. " }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 262 12 "E xample 11.4" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 139 "Suppose that a sp here of radius a contains a material whose density obeys an inverse sq uare law relative to the center of the sphere: i.e. " }{XPPEDIT 18 0 " D = K/(r^2);" "6#/%\"DG*&%\"KG\"\"\"*$%\"rG\"\"#!\"\"" }{TEXT -1 139 " where r is the distance from the center. What is the total quantity of material in the sphere. With the methodology in hand we compute \+ " }{XPPEDIT 18 0 "Int(D,V);" "6#-%$IntG6$%\"DG%\"VG" }{TEXT -1 1 "." } }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 64 "restart: with(plots): with (LinearAlgebra): with(VectorCalculus):" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 57 "We will use the geographi c parametrization of the sphere." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 64 "S := ;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "rho := K/r^2 :" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 37 "J[v] := Jacobian(S, [r , phi, theta]);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 66 "dV := si mplify(sqrt(Determinant(Transpose(J[v]).J[v])), symbolic);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 62 "Int(Int(Int(rho*dV, phi=-Pi/2..Pi/2 ), theta=0..2*Pi), r=0..a);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 9 "value(%);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 103 "If a number of e xpressions are to be reparameterized it pays to define a simple functi on to do the job." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 " " 0 "" {TEXT 263 12 "Example 11.5" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 232 "We suppose that we have a measure ment of some physical quantity, F, in a cylindrical container of radiu s a, and height h, that depends on the radial distance from the center of the cylinder and the height above the cylinder's base. " } {XPPEDIT 18 0 "F = (x^2+y^2)/(z+1);" "6#/%\"FG*&,&*$%\"xG\"\"#\"\"\"*$ %\"yGF)F*F*,&%\"zGF*F*F*!\"\"" }{TEXT -1 313 " We want to integrate t his quantity over the entire cylinder. We take advantage of the symme tries present and locate the base of the cylinder on the z=0 plane and the center of the base at the origin. Then, to avoid the problems of negative trigonometric functions, we work in the first quadrant of th e plane. " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 62 "restart:with(p lots):with(LinearAlgebra): with(VectorCalculus):" }}}{EXCHG {PARA 0 " " 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 96 "We start by defini ng a function to do the work of reparameterizing into cylindrical coor dinates." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 65 "f := g->simplif y(subs(\{x=r*cos(theta), y=r*sin(theta), z=z\}, g)):" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 35 "Define the elem ents of the problem." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "F : = r/(z+1);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 29 "cyl := ;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 185 "We have defi ned only one half of the cylinder. Now we reparameterize the half-cyl inder. We need a couple of assume statements so that Maple doesn't pri nt a bunch of messy csgn symbols." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 25 "interface(showassumed=0):" }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 33 "assume(sin(theta)>0):assume(r>0):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "C := f(cyl);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 34 "The calculation proceeds as usual." }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 32 "J := Jacobian(C, [r, theta, z]);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 60 "dV := simplify(sqrt(Determinant(Tra nspose(J).J)), symbolic);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "FdV := F*dV;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 86 "The integrati on is taken over the part of the cylinder lying over the first quadran t. " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 50 "Int(Int(Int(FdV, the ta=0..Pi/2), z=0..h), r=0..a);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 11 "4*value(%);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 118 "It is alw ays a good idea to test new methods against known results. We will fi nd the volume of a solid of revolution." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 264 12 "Example 11.5" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 31 "Given a c urve parameterized by " }{XPPEDIT 18 0 "f(t) = [x(t), y(t)];" "6#/-%\" fG6#%\"tG7$-%\"xG6#F'-%\"yG6#F'" }{TEXT -1 95 " , find the volume of t he solid formed by rotating the curve around the x axis from x=a to x= b." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 64 "restart: with(plots): with(LinearAlgebra): with(VectorCalculus):" }}}{EXCHG {PARA 0 "" 0 " " {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 58 "Transformation to cylin drical coordinates about the x-axis" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 50 "V := ;" } }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 32 "J := Jacobian(V, [s, theta , t]);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 60 "dV := simplify(sq rt(Determinant(Transpose(J).J)), symbolic);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 59 "Volume := Int(Int(Int(dV, s=0..1), t=a..b), theta= 0..2*Pi);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 19 "simplify(value (%));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 58 "A result familiar from t he calculus of a single variable. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 265 8 "Practice" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 66 "1. Find the volume of the solid whose sur face is parameterized by:" }}{PARA 0 "" 0 "" {TEXT -1 7 " " } {XPPEDIT 18 0 "[(phi+2*cos(theta))*cos(phi), (phi+2*cos(theta))*sin(ph i), 2*sin(theta)];" "6#7%*&,&%$phiG\"\"\"*&\"\"#F'-%$cosG6#%&thetaGF'F 'F'-F+6#F&F'*&,&F&F'*&F)F'-F+6#F-F'F'F'-%$sinG6#F&F'*&F)F'-F66#F-F'" } {TEXT -1 4 " , " }{XPPEDIT 18 0 "phi;" "6#%$phiG" }{TEXT -1 3 " = " } {XPPEDIT 18 0 "Pi .. 4*Pi;" "6#;%#PiG*&\"\"%\"\"\"F$F'" }{TEXT -1 3 " \+ , " }{XPPEDIT 18 0 "theta = 0 .. 2*Pi;" "6#/%&thetaG;\"\"!*&\"\"#\"\" \"%#PiGF)" }{TEXT -1 1 " " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 57 "2. F ind the volume of the solid enclosed in the surface; " }{XPPEDIT 18 0 "z = x^4+y^4;" "6#/%\"zG,&*$%\"xG\"\"%\"\"\"*$%\"yGF(F)" }{TEXT -1 3 " , " }{XPPEDIT 18 0 "-1 <= x;" "6#1,$\"\"\"!\"\"%\"xG" }{TEXT -1 2 ", \+ " }{XPPEDIT 18 0 "y <= 1;" "6#1%\"yG\"\"\"" }{TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 41 "3. Find the volume of the elliptic cone: \+ " }{XPPEDIT 18 0 "z^2 = 5*x^2+y^2;" "6#/*$%\"zG\"\"#,&*&\"\"&\"\"\"*$% \"xGF&F*F**$%\"yGF&F*" }{TEXT -1 27 " whose height is 5 units. " }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 110 "4. A cylinder of elliptical cross section, 6x10 units wide and 100 units high contains a gas whose dens ity is " }{XPPEDIT 18 0 "2*exp(-.1*d);" "6#*&\"\"#\"\"\"-%$expG6#,$*&- %&FloatG6$F%!\"\"F%%\"dGF%F.F%" }{TEXT -1 102 "where d is the distance from the base of the cylinder. Find the total mass of the gas in the \+ cylinder." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 243 "5. Given a cylinder of radius 2 units and height h, and a material whose concentration i s proportional to the square of the distance from the center of the ba se of the cylinder, find the total amount of the material contained in the cylinder." }}}}{MARK "0 0 2" 0 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }