{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 60 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 "Define" -1 256 "Times" 1 12 163 163 163 0 1 1 0 0 0 0 0 0 0 1 }{CSTYLE "Emphasis" -1 257 "Times" 1 12 128 0 128 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "normal C" -1 258 "Times" 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "Menu" -1 259 "" 0 0 163 163 163 0 0 1 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 260 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE " " -1 261 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 262 "Symbol" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 263 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 264 "Symbol" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 265 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 266 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 267 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 268 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE " " -1 269 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 270 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 271 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 272 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 273 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 274 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 275 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 276 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE " " -1 277 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 278 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 279 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 280 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 281 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 282 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 283 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE " " -1 284 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 285 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 286 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 287 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 288 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 } {CSTYLE "" -1 289 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 290 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 291 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 292 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 293 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 294 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 295 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "Geneva" 1 10 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 "R3 Font 0" -1 256 1 {CSTYLE "" -1 -1 "Mona co" 1 9 255 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 "R3 Font 2" -1 257 1 {CSTYLE "" -1 -1 "Symbol" 1 10 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 "R3 Font 0" -1 258 1 {CSTYLE "" -1 -1 "Geneva" 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 }} {SECT 0 {EXCHG {PARA 258 "" 0 "" {TEXT 257 41 "COMPLEX ANALYSIS: Maple Worksheets, 2001" }{TEXT 280 144 "\n(c) John H. Mathews Rus sell W. Howell\nmathews@fullerton.edu howell@westmont.edu\n\nCompl imentary software to accompany the textbook:" }}{PARA 258 "" 0 "" {TEXT 257 82 "COMPLEX ANALYSIS: for Mathematics & Engineering, 4th Ed, 2001, ISBN: 0-7637-1425-9" }{TEXT 279 197 "\nJones and Bartlett Publi shers, Inc., 40 Tall Pine Drive, Sudbury, MA 01776\nTel e. (800) 832-0034; FAX: (508) 443-8000, E-mail: mkt@jbpu b.com, http://www.jbpub.com/" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 278 1 "\n" }{TEXT 256 31 "CHAPTER 5 ELEMENTARY FUNCTIONS" }{TEXT 273 2 "\n\n" }{TEXT 256 45 "Section 5.1 The Complex Exponential Function " }{TEXT 274 3 "\n\n " }{TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 47 " \+ How should complex-valued functions such as " }{XPPEDIT 18 0 "exp(z) ;" "6#-%$expG6#%\"zG" }{TEXT -1 2 ", " }{XPPEDIT 18 0 "log(z);" "6#-%$ logG6#%\"zG" }{TEXT -1 2 ", " }{XPPEDIT 18 0 "sin(z);" "6#-%$sinG6#%\" zG" }{TEXT -1 94 ", etc., be defined? Clearly, any responsible definit ion should satisfy the following criteria:" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 290 2 "i." }{TEXT -1 119 " The functi ons so defined must give the same values as the corresponding function s for real variables when the number " }{XPPEDIT 18 0 "z;" "6#%\"zG" } {TEXT -1 20 " is a real number. " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }} {PARA 0 "" 0 "" {TEXT 291 3 "ii." }{TEXT -1 131 " As far as possible, \+ the properties of these new functions must correspond with their real \+ counterparts. For example, we would want" }}{PARA 0 "" 0 "" {TEXT -1 7 " " }{XPPEDIT 18 0 "exp(z[1]+z[2]) = exp(z[1])*exp(z[2]);" "6# /-%$expG6#,&&%\"zG6#\"\"\"F+&F)6#\"\"#F+*&-F%6#&F)6#F+F+-F%6#&F)6#F.F+ " }{TEXT -1 3 " " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 35 "to be valid regardless of whether " }{XPPEDIT 18 0 "z[1] ;" "6#&%\"zG6#\"\"\"" }{TEXT -1 7 " and " }{XPPEDIT 18 0 "z[2];" "6# &%\"zG6#\"\"#" }{TEXT -1 23 " were real or complex." }}{PARA 0 "" 0 " " {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 169 " These requirements \+ may seem like a tall order to fill. There is a procedure, however, tha t offers promising results. It is to put the expansion of the real fun ctions " }{XPPEDIT 18 0 "exp(z);" "6#-%$expG6#%\"zG" }{TEXT -1 2 ", " }{XPPEDIT 18 0 "log(z);" "6#-%$logG6#%\"zG" }{TEXT -1 2 ", " } {XPPEDIT 18 0 "sin(z);" "6#-%$sinG6#%\"zG" }{TEXT -1 94 ", etc., as po wer series into complex form. This will be our stategy for the next fe w sections." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 84 " Recall that \+ the real exponential function can be represented by the power series \+ " }{XPPEDIT 18 0 "exp(x) = Sum(x^n/n!,n = 0 .. infinity);" "6#/-%$expG 6#%\"xG-%$SumG6$*&)F'%\"nG\"\"\"-%*factorialG6#F-!\"\"/F-;\"\"!%)infin ityG" }{TEXT -1 62 " . Thus it is only natural to define the complex \+ exponential " }{XPPEDIT 18 0 "exp(z);" "6#-%$expG6#%\"zG" }{TEXT -1 18 ", also written as " }{XPPEDIT 18 0 "`exp(z)`" "6#%'exp(z)G" } {TEXT -1 23 ", in the following way:" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 256 49 "Definition 5.1: The complex e xponential function" }{TEXT -1 3 " " }}{PARA 0 "" 0 "" {TEXT -1 0 " " }}{PARA 0 "" 0 "" {TEXT 292 6 " " }{XPPEDIT 18 0 "exp(z)" "6#-% $expG6#%\"zG" }{TEXT 283 5 " = " }{XPPEDIT 18 0 "`exp(z)`;" "6#%'exp (z)G" }{TEXT 284 6 " = " }{XPPEDIT 18 0 "sum(z^n/n!,n = 0 .. infini ty);" "6#-%$sumG6$*&)%\"zG%\"nG\"\"\"-%*factorialG6#F)!\"\"/F);\"\"!%) infinityG" }{TEXT 282 3 " \n" }{TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 79 "Clearly this definition agrees with that of the real exponentia l function when " }{XPPEDIT 18 0 "z;" "6#%\"zG" }{TEXT -1 20 " is a re al number. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 281 103 "Load Maple's \+ \"conformal mapping\" procedure.\nMake sure this is done only ONCE du ring a Maple session.\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "with(pl ots):" }{TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 8 "Theorem." }{TEXT 275 72 " The exponential fun ction is a solution to the differential equation " }{XPPEDIT 18 0 "`f '(z)` = f(z)" "6#/%'f~'(z)G-%\"fG6#%\"zG" }{TEXT 269 30 " with the i nitial condition " }{XPPEDIT 18 0 "f(0) = 1" "6#/-%\"fG6#\"\"!\"\"\" " }{TEXT 270 3 " .\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 128 "f:='f': z: ='z': Z:='Z':\nf := z -> exp(z):\nf1 := z -> subs(Z=z, diff(f(Z),Z)): \n`f(z) ` = f(z);\n`f '(z) ` = f1(z);\n`f(0) ` = f(0);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 260 57 " To see its real and imaginary parts, use complex expand.\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 84 "x:='x': y:='y': Z:='Z':\nZ := x + I*y:\n`ex p(z) ` = exp(Z);\n`exp(z) ` = evalc(exp(Z));" }}}{EXCHG {PARA 0 "" 0 " " {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 261 46 "Now verify tha t the \"rules of exponents\" hold." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }} {PARA 0 "> " 0 "" {MPLTEXT 1 0 483 "x:='x': y:='y': z:='z': \nw1 := ev alc(exp(x[1]+I*y[1])):\nw2 := evalc(exp(x[2]+I*y[2])):\nw3 := w1*w2: e xp(z[1])*exp(z[2]) = w3; ` `;\nw3 := evalc(w1*w2): exp(z[1])*exp(z[2]) = w3; ` `;\nw3 := expand(w3): exp(z[1])*exp(z[2]) = w3; ` `;\nz4 := ( x[1]+I*y[1])+(x[2]+I*y[2]):\nw4 := exp(z4): exp(z[1]*z[2]) = w4; ` `; \nw4 := evalc(exp(z4)): exp(z[1]*z[2]) = w4; ` `;\nw4 := expand(w4, tr ig): exp(z[1]*z[2]) = w4; ` `;\n`Does exp(z1 z2) = exp(z1) exp(z2) ? `;\nw3 = w4; ` `;\nevalb(expand(w3 = w4));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 " " {TEXT 256 11 "Theorem 5.1" }{TEXT 285 3 " " }{TEXT -1 14 "The func tion " }{XPPEDIT 18 0 "`exp(z)` = exp(z);" "6#/%'exp(z)G-%$expG6#%\"z G" }{TEXT -1 36 " is an entire function satisfying:\n" }}{PARA 0 "" 0 "" {TEXT 293 2 "i." }{TEXT -1 4 " " }{XPPEDIT 18 0 "`exp'(z) = ex p(z)` = exp(z)" "6#/%1exp'(z)~=~exp(z)G-%$expG6#%\"zG" }{TEXT -1 32 " \+ (Using Leibniz notation, " }{XPPEDIT 18 0 "Diff(exp(z),z) = exp( z);" "6#/-%%DiffG6$-%$expG6#%\"zGF*-F(6#F*" }{TEXT -1 5 ".) \n" }} {PARA 0 "" 0 "" {TEXT 294 3 "ii." }{TEXT -1 3 " " }{TEXT 286 4 "exp( " }{XPPEDIT 18 0 "z[1]+z[2];" "6#,&&%\"zG6#\"\"\"F'&F%6#\"\"#F'" } {TEXT 287 8 ") = exp(" }{XPPEDIT 18 0 "z[1];" "6#&%\"zG6#\"\"\"" } {TEXT 288 5 ")exp(" }{XPPEDIT 18 0 "z[2];" "6#&%\"zG6#\"\"#" }{TEXT 289 1 ")" }{TEXT -1 17 " (That is, " }{XPPEDIT 18 0 "exp(z[1]+z[ 2]) = exp(z[1])*exp(z[2])" "6#/-%$expG6#,&&%\"zG6#\"\"\"F+&F)6#\"\"#F+ *&-F%6#&F)6#F+F+-F%6#&F)6#F.F+" }{TEXT -1 3 ".)\n" }}{PARA 0 "" 0 "" {TEXT 295 5 "iii. " }{TEXT -1 4 " If " }{XPPEDIT 18 0 "theta;" "6#%&th etaG" }{TEXT -1 26 " is a real number, then " }{XPPEDIT 18 0 "exp(i* theta) = cos(theta)+i*sin(theta);" "6#/-%$expG6#*&%\"iG\"\"\"%&thetaGF ),&-%$cosG6#F*F)*&F(F)-%$sinG6#F*F)F)" }{TEXT -1 4 ". " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 22 "Example 5.1, Page 164." }{TEXT 276 15 " The points " }{XPPEDIT 18 0 "z[n] = 5/4 + i*(11*pi/6 + 2*n*pi)" " 6#/&%\"zG6#%\"nG,&*&\"\"&\"\"\"\"\"%!\"\"F+*&%\"iGF+,&*(\"#6F+%#piGF+ \"\"'F-F+*(\"\"#F+F'F+F3F+F+F+F+" }{TEXT 267 69 " for \nn =..., -2, - 1, 0, 1, 2, ... are mapped onto a single point " }{XPPEDIT 18 0 "w[0 ] = exp(z[n])" "6#/&%\"wG6#\"\"!-%$expG6#&%\"zG6#%\"nG" }{TEXT 268 3 " .\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 92 "Z0 := 5/4 + I*11*Pi/6:\nfor k from 0 to 5 do\n exp(Z0+I*2*Pi*k)=evalc(exp(Z0+I*2*Pi*k)); \nod;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 22 "Example 5.2, Page 166." }{TEXT 277 33 " Show that the transformation " }{XPPEDIT 18 0 "w = \+ exp(z)" "6#/%\"wG-%$expG6#%\"zG" }{TEXT 271 23 " maps the rectangle \+ \n" }{XPPEDIT 18 0 "`R = \{(x,y): a <= x <= b and c <= y <= d\}`" "6# %JR~=~|fr(x,y):~~a~<=~x~<=~b~and~c~<=~y~<=~d|hrG" }{TEXT 272 119 " on to a portion of an annular region bounded by two rays.\nFor illustrati on we use R = \{(x,y): -1 <= x <= 1 and - " }{TEXT 262 1 "p" } {TEXT 263 12 "/3 <= y <= " }{TEXT 264 1 "p" }{TEXT 265 6 "/4\} .\n" } }{PARA 0 "> " 0 "" {MPLTEXT 1 0 229 "f:='f': z:='z':\nf := z -> exp(z) :\n`f(z) ` = f(z);\nconformal(f(z), z=-1-I*Pi/3..1+I*Pi/4,\n title=`w = exp(z)`,\n grid=[8,8],numxy=[50,50],\n scaling=constrained,\n la bels=[`u`,`v `],\n tickmarks=[3,5],\n view=[0..2.8,-2.4..2.0]);" }}} {EXCHG {PARA 0 "" 0 "" {TEXT 266 19 "End of Section 5.1." }}}}{MARK "0 0 0" 29 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }