{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 0 }{CSTYLE "" -1 257 "" 0 1 0 0 0 0 1 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 258 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 259 "" 0 1 0 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 0 } {CSTYLE "" -1 261 "" 0 1 0 0 0 0 1 1 0 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 0 }{CSTYLE "" -1 263 "" 0 1 0 0 0 0 0 1 0 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 0 }{CSTYLE "" -1 268 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 } {CSTYLE "" -1 272 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 274 "" 0 1 0 0 0 0 1 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 275 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 276 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 277 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 } {CSTYLE "" -1 279 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{PSTYLE "Normal " -1 0 1 {CSTYLE "" -1 -1 "Times" 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 1" -1 3 1 {CSTYLE "" -1 -1 "Times" 1 18 0 0 0 1 2 1 2 2 2 2 1 1 1 1 }1 1 0 0 8 4 1 0 1 0 2 2 0 1 }{PSTYLE "Title" -1 18 1 {CSTYLE "" -1 -1 "Times" 1 18 0 0 0 1 2 1 1 2 2 2 1 1 1 1 }3 1 0 0 12 12 1 0 1 0 2 2 19 1 }{PSTYLE "Normal" -1 256 1 {CSTYLE "" -1 -1 "Times" 1 12 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 1 2 2 2 2 1 1 1 1 }1 1 0 0 0 0 1 0 1 0 2 2 0 1 }} {SECT 0 {EXCHG {PARA 18 "" 0 "" {TEXT -1 46 "Experiments on Limits and Linear Approximation" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 81 " \+ Version .7 Maple \+ VR7" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 39 "These packages need to be \+ loaded first." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 43 "with(plots): with( linalg): with(plottools):" }}}{SECT 1 {PARA 3 "" 0 "" {TEXT -1 22 " Li mits and Graphs in " }{XPPEDIT 18 0 "R^3;" "6#*$)%\"RG\"\"$\"\"\"" } {TEXT -1 0 "" }}{EXCHG {PARA 0 "" 0 "" {TEXT -1 86 "Look at the graph \+ below. Perhaps try changing the value of eps and rotating the graph." }}{PARA 0 "" 0 "" {TEXT 279 63 "What does this say about the limit as \+ (x,y) approaches (0,0) of" }{TEXT -1 1 " " }{XPPEDIT 18 0 "sin((x-y)^2 )/(x^2+y^2);" "6#*&-%$sinG6#*$),&%\"xG\"\"\"%\"yG!\"\"\"\"#F+F+,&*$)F* F.F+F+*$)F,F.F+F+F-" }{TEXT -1 1 "?" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 8 "eps:=.5;" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 67 "plot3d(sin((x-y)^2)/ (x^2+y^2),x=-eps..eps,y=-eps..eps,axes=framed);" }}}{PARA 3 "" 0 "" {TEXT -1 0 "" }}{EXCHG {PARA 0 "" 0 "" {TEXT -1 83 "The animation belo w shows the y= kx sections of this graph for various values of k." }} {PARA 0 "" 0 "" {TEXT -1 87 "To play the animation, click on the graph and then choose play from the animation menu." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }{TEXT 272 64 "Why does the animation tell you something about the above limit?" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 64 "animate( subs(y=k*x,sin((x-y)^2)/(x^2+y^2)),x=-eps..eps,k=-3..3);" }}}}{SECT 1 {PARA 3 "" 0 "" {TEXT -1 44 "Some Linear Approximations for a function F:" }{XPPEDIT 18 0 "R^2;" "6#*$)%\"RG\"\"#\"\"\"" }{TEXT -1 2 "->" } {XPPEDIT 18 0 "R^2;" "6#*$)%\"RG\"\"#\"\"\"" }{TEXT -1 1 "." }}{EXCHG {PARA 0 "" 0 "" {TEXT 256 147 "Try changing the scale below - at least for the values scale =.1,.5 and 1. \n(You need to re-execute the line s which follow after you change scale.)" }}{PARA 0 "" 0 "" {TEXT -1 76 "The pictures compare the image of a certain square under the funct ion F with" }}{PARA 0 "" 0 "" {TEXT -1 80 "the image of the square und er the linear approximation obtained at the center of" }}{PARA 0 "" 0 "" {TEXT -1 12 "the square.\n" }{TEXT 258 12 "Compare the " }{TEXT 257 8 "accuracy" }{TEXT 259 68 " of linear approximation as a function of the size of the rectangle." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 11 "Defining F:" }{XPPEDIT 18 0 "R^2;" "6#*$)%\"RG\"\"#\"\"\"" }{TEXT -1 2 "->" }{XPPEDIT 18 0 "R^2;" "6#*$)%\"RG\"\"#\"\"\"" }{TEXT -1 4 " by \+ " }{XPPEDIT 18 0 "F(x,y) = (exp(x)+y, exp(y)+x);" "6#/-%\"FG6$%\"xG%\" yG6$,&-%$expG6#F'\"\"\"F(F.,&-F,6#F(F.F'F." }{TEXT -1 42 ". DF is its \+ derivative at the point (x,y)." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 63 "F :=(x,y)->[1-exp(x)-y,1-exp(y)-x]; DF:=jacobian(F(x,y),[x,y]);\n" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 100 "We will be linearizing F at the p oint p0. And scale controls the size of the rectangle we work with." } }{PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "scale:=1;\np0:=[.5*scale,.5*scale] ;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 65 "An easy way to draw a square with corner (0,0) and (scale,scale)." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 87 "gr1:=conformal(z,z=0..scale*(1+I)):\ngr1a:=conformal(z,z=0..scal e*(1+I),color=magenta):\n" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 74 "This picture shows the original rectangle together with its image under F. " }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 81 "F_gr:=transform(F):\ndisplay([g r1,F_gr(gr1)],title=`Image of Rectangle under F`);\n" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 121 "Below is the corresponding picture under the l inearization of F at p0.\nDon't worry necessarily about the Maple code , but " }}{PARA 0 "" 0 "" {TEXT -1 88 " F0= the image of the point p0 under F.\n L=derivative DF at p0 (a 2 by 2 matrix)" }}{PARA 0 "" 0 "" {TEXT -1 43 " L1=the linear approximation of F at p0" }} {PARA 0 "" 0 "" {TEXT -1 55 " L2=a different form of L1 for Maple \+ syntax reasons" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 251 "F0:=F(op(p0));\n L:=map(evalf,subs(\{x=p0[1],y=p0[2]\},eval(DF)));\nL1:=convert(evalm(L &*vector([x-p0[1],y-p0[2]])+F0),list);\nL2:=unapply(L1,[x,y]);\nL2_gr :=transform(L2):\ndisplay([gr1a,L2_gr(gr1a)],title=`Image of Rectangle under Linear Approximation`);\n\n" }}}}{SECT 1 {PARA 3 "" 0 "" {TEXT -1 28 "Linearization at the Origin." }}{EXCHG {PARA 0 "" 0 "" {TEXT 264 75 "Try changing the scale below - at least for the values scale = .1,.5 and 1. " }}{PARA 0 "" 0 "" {TEXT 268 52 "Why do the linearized p ictures look the way they do?" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 11 " Defining F:" }{XPPEDIT 18 0 "R^2;" "6#*$%\"RG\"\"#" }{TEXT -1 2 "->" } {XPPEDIT 18 0 "R^2;" "6#*$%\"RG\"\"#" }{TEXT -1 4 " by " }{XPPEDIT 18 0 "F(x,y) = (exp(x)+y, exp(y)+x);" "6#/-%\"FG6$%\"xG%\"yG6$,&-%$expG6# F'\"\"\"F(F.,&-F,6#F(F.F'F." }{TEXT -1 42 ". DF is its derivative at t he point (x,y)." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 63 "F:=(x,y)->[1-exp (x)-y,1-exp(y)-x]; DF:=jacobian(F(x,y),[x,y]);\n" }}}{EXCHG {PARA 0 " " 0 "" {TEXT -1 100 "We will be linearizing F at the point p0. And sca le controls the size of the rectangle we work with." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 22 "scale:=0.1;\np0:=[0,0];" }}}{EXCHG {PARA 0 "" 0 " " {TEXT -1 65 "An easy way to draw a square with corner (0,0) and (sca le,scale)." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 87 "gr1:=conformal(z,z=0. .scale*(1+I)):\ngr1a:=conformal(z,z=0..scale*(1+I),color=magenta):\n" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 74 "This picture shows the original rectangle together with its image under F." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 81 "F_gr:=transform(F):\ndisplay([gr1,F_gr(gr1)],title=`I mage of Rectangle under F`);\n" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 121 "Below is the corresponding picture under the linearization of F a t p0.\nDon't worry necessarily about the Maple code, but " }}{PARA 0 " " 0 "" {TEXT -1 88 " F0= the image of the point p0 under F.\n \+ L=derivative DF at p0 (a 2 by 2 matrix)" }}{PARA 0 "" 0 "" {TEXT -1 43 " L1=the linear approximation of F at p0" }}{PARA 0 "" 0 "" {TEXT -1 55 " L2=a different form of L1 for Maple syntax reasons" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 251 "F0:=F(op(p0));\nL:=map(evalf,sub s(\{x=p0[1],y=p0[2]\},eval(DF)));\nL1:=convert(evalm(L &*vector([x-p0[ 1],y-p0[2]])+F0),list);\nL2:=unapply(L1,[x,y]);\nL2_gr:=transform(L2): \ndisplay([gr1a,L2_gr(gr1a)],title=`Image of Rectangle under Linear Ap proximation`);\n\n" }}}{PARA 3 "" 0 "" {TEXT -1 0 "" }}}{SECT 1 {PARA 3 "" 0 "" {TEXT -1 19 "Another function F:" }{XPPEDIT 18 0 "R^2;" "6#* $%\"RG\"\"#" }{TEXT -1 2 "->" }{XPPEDIT 18 0 "R^2;" "6#*$%\"RG\"\"#" } {TEXT -1 1 "." }}{EXCHG {PARA 0 "" 0 "" {TEXT 260 150 "Try changing th e scale below - at least for the values scale =1, .5, .1, .01. \n(You \+ need to re-execute the lines which follow after you change scale.)" }} {PARA 0 "" 0 "" {TEXT -1 76 "The pictures compare the image of a certa in square under the function F with" }}{PARA 0 "" 0 "" {TEXT -1 80 "th e image of the square under the linear approximation obtained at the c enter of" }}{PARA 0 "" 0 "" {TEXT -1 12 "the square.\n" }{TEXT 262 12 "Compare the " }{TEXT 261 8 "accuracy" }{TEXT 263 68 " of linear appro ximation as a function of the size of the rectangle." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 55 "F:=(x,y)->[x^2-y^2,2*x*y]; DF:=jacobian(F(x,y),[x,y]);\n" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 100 "We will be linearizing F at the p oint p0. And scale controls the size of the rectangle we work with." } }{PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "scale:=1;\np0:=[.5*scale,.5*scale] ;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 67 "An easy way to draw a square with corner (0,0) and (-scale,-scale)." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 89 "gr1:=conformal(z,z=0..scale*(-1-I)):\ngr1a:=conformal(z,z=0..s cale*(-1-I),color=magenta):\n" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 74 " This picture shows the original rectangle together with its image unde r F." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 81 "F_gr:=transform(F):\ndispla y([gr1,F_gr(gr1)],title=`Image of Rectangle under F`);\n" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 121 "Below is the corresponding picture under the linearization of F at p0.\nDon't worry necessarily about the Mapl e code, but " }}{PARA 0 "" 0 "" {TEXT -1 88 " F0= the image of the point p0 under F.\n L=derivative DF at p0 (a 2 by 2 matrix)" }} {PARA 0 "" 0 "" {TEXT -1 43 " L1=the linear approximation of F at \+ p0" }}{PARA 0 "" 0 "" {TEXT -1 55 " L2=a different form of L1 for \+ Maple syntax reasons" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 251 "F0:=F(op(p 0));\nL:=map(evalf,subs(\{x=p0[1],y=p0[2]\},eval(DF)));\nL1:=convert(e valm(L &*vector([x-p0[1],y-p0[2]])+F0),list);\nL2:=unapply(L1,[x,y]); \nL2_gr:=transform(L2):\ndisplay([gr1a,L2_gr(gr1a)],title=`Image of Re ctangle under Linear Approximation`);\n\n" }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 0 "" }}}}{SECT 1 {PARA 3 "" 0 "" {TEXT -1 44 "Some Line ar Approximations for a function F:" }{XPPEDIT 18 0 "R^2;" "6#*$)%\"RG \"\"#\"\"\"" }{TEXT -1 2 "->" }{XPPEDIT 18 0 "R^3;" "6#*$)%\"RG\"\"$\" \"\"" }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 76 "The pictures comp are the image of a certain square under the function F with" }}{PARA 0 "" 0 "" {TEXT -1 80 "the image of the square under the linear approx imation obtained at the center of" }}{PARA 0 "" 0 "" {TEXT -1 12 "the \+ square.\n" }}{PARA 0 "" 0 "" {TEXT 277 86 "Try changing the scale belo w - at least for the values scale =2, 1, .5, .25, and .1. " }{TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 275 12 "Compare the " }{TEXT 274 8 "ac curacy" }{TEXT 276 68 " of linear approximation as a function of the s ize of the rectangle." }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 76 "F:= (x,y)->[sin(x)*cos(y),sin(x)*sin(y),cos(x)]; DF:=jacobian(F(x,y),[x,y] );\n" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 100 "We will be linearizing F at the point p0. And scale controls the size of the rectangle we work with." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "scale:=1;\np0:=[.5*scale, .5*scale];" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 65 "An easy way to draw a square with corner (0,0) and (scale,scale)." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 102 "gr1:=conformal(z,z=0..scale*(1+I)):\ngr1a:=conformal (z,z=0..scale*(+1+I),color=magenta):\ndisplay(gr1);\n" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 37 "This picture shows the image under F." }} {PARA 0 "" 0 "" {TEXT -1 83 "The option scaling=constrained means to c hoose the same scale along all three axes." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 107 "F_gr:=transform(F):\ndisplay(F_gr(gr1),title=`Image \+ of Rectangle under F`,axes=framed,scaling=constrained);\n" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 117 "Below is the picture of the image of the rectangle under the linearization of F at p0 together with the actual image." }}{PARA 0 "" 0 "" {TEXT -1 50 "Don't worry necessarily about \+ the Maple code, but " }}{PARA 0 "" 0 "" {TEXT -1 88 " F0= the imag e of the point p0 under F.\n L=derivative DF at p0 (a 2 by 2 matri x)" }}{PARA 0 "" 0 "" {TEXT -1 43 " L1=the linear approximation of F at p0" }}{PARA 0 "" 0 "" {TEXT -1 55 " L2=a different form of L 1 for Maple syntax reasons" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 277 "F0:= F(op(p0));\nL:=map(evalf,subs(\{x=p0[1],y=p0[2]\},eval(DF)));\nL1:=con vert(evalm(L &*vector([x-p0[1],y-p0[2]])+F0),list);\nL2:=unapply(L1,[x ,y]);\nL2_gr:=transform(L2):\ndisplay([F_gr(gr1),L2_gr(gr1a)],title=`I mage and its Linear Approximation`,axes=framed,scaling=constrained);\n \n" }}}{PARA 3 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 256 "" 0 "" {TEXT -1 68 "You could also try the above without the scaling=constrai ned option." }}{PARA 257 "" 0 "" {TEXT -1 34 "Can you explain what hap pens then?" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{MARK "1 0 0" 62 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }