{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 1 174 178 216 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 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 263 "Gene va" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 264 "Geneva" 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 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 280 "Geneva" 1 10 0 0 0 1 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 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 286 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 287 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 288 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 289 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 290 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 291 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 292 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE " " -1 293 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 294 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 295 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 296 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 297 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 298 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 299 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 300 "Geneva" 1 10 0 0 0 1 0 0 0 0 0 0 0 0 0 1 }{CSTYLE " " -1 301 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 302 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 303 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 304 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{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 "Monaco" 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 286 144 "\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 285 197 "\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 284 1 "\n" }{TEXT 256 26 "CHAPTER 8 RESIDUE THEORY" }{TEXT 279 2 "\n \n" }{TEXT 256 32 "Section 8.1 The Residue Theorem" }{TEXT 280 7 "\n \n " }{TEXT -1 116 "The Cauchy-integral formulas in Section 6.5 ar e useful in evaluating contour integrals over a simple closed contour \+ " }{XPPEDIT 18 0 "C;" "6#%\"CG" }{TEXT -1 35 " where the integrand has the form " }{XPPEDIT 18 0 "f(z)/((z-z[0])^k);" "6#*&-%\"fG6#%\"zG\" \"\"),&F'F(&F'6#\"\"!!\"\"%\"kGF." }{TEXT -1 7 " and " }{XPPEDIT 18 0 "f;" "6#%\"fG" }{TEXT -1 103 " is an analytic function. In this ca se, the singularity of the integrand is at worst a pole of order " } {XPPEDIT 18 0 "k" "6#%\"kG" }{TEXT -1 5 " at " }{XPPEDIT 18 0 "z[0]" "6#&%\"zG6#\"\"!" }{TEXT -1 133 ". In this section we extend this res ult to integrals that have a finite number of isolated singularities a nd lie inside the contour " }{XPPEDIT 18 0 "C" "6#%\"CG" }{TEXT -1 93 ". This new method can be used in cases where the integrand has an es sential singularity at " }{XPPEDIT 18 0 "z[0]" "6#&%\"zG6#\"\"!" } {TEXT -1 57 " and is an important extension of the previous method. \+ " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 24 "Definition 8.1: Residue" }{TEXT 299 2 " " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 300 5 "Let " }{XPPEDIT 18 0 "f( z)" "6#-%\"fG6#%\"zG" }{TEXT 289 57 " have a nonremovable isolated si ngularity at the point " }{XPPEDIT 18 0 "z[0]" "6#&%\"zG6#\"\"!" } {TEXT 290 10 " . Then " }{XPPEDIT 18 0 "f(z)" "6#-%\"fG6#%\"zG" } {TEXT 291 42 " has \nthe Laurent series representation " }{XPPEDIT 18 0 "f(z) = sum(a[n]*(z-z0)^n, n=-infinity..infinity)" "6#/-%\"fG6#% \"zG-%$sumG6$*&&%\"aG6#%\"nG\"\"\"),&F'F0%#z0G!\"\"F/F0/F/;,$%)infinit yGF4F8" }{TEXT 288 22 " . The coefficient " }{XPPEDIT 18 0 "a[-1]" "6#&%\"aG6#,$\"\"\"!\"\"" }{TEXT 292 6 " of " }{XPPEDIT 18 0 "1/(z-z [0])" "6#*&\"\"\"F$,&%\"zGF$&F&6#\"\"!!\"\"F*" }{TEXT 293 17 " is \nc alled the " }{TEXT 257 7 "residue" }{TEXT 298 5 " of " }{XPPEDIT 18 0 "f(z)" "6#-%\"fG6#%\"zG" }{TEXT 294 6 " at " }{XPPEDIT 18 0 "z[0] " "6#&%\"zG6#\"\"!" }{TEXT 295 35 " and we use the notation Res[f , \+ " }{XPPEDIT 18 0 "z[0]" "6#&%\"zG6#\"\"!" }{TEXT 296 4 "] = " } {XPPEDIT 18 0 "a[-1]" "6#&%\"aG6#,$\"\"\"!\"\"" }{TEXT 297 4 " . " } {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 287 93 "Load Maple's \"residue\" procedure.\nMake sur e this is done only ONCE during a Maple session.\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 17 "readlib(residue):" }{TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 256 22 "Example 8.1, Page 307." }{TEXT 281 46 " Use \+ Laurent series to find the residue at " }{XPPEDIT 18 0 "z = 0" "6#/% \"zG\"\"!" }{TEXT 264 20 " for the function " }{XPPEDIT 18 0 "f(z) = exp(2/z)" "6#/-%\"fG6#%\"zG-%$expG6#*&\"\"#\"\"\"F'!\"\"" }{TEXT 265 3 " .\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 106 "f:='f': s:='s': z:='z': \nf := z -> exp(2/z):\ns := series(f(z), z=infinity, 7):\n`f(z) ` = f( z);\n`f(z) ` = s;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 260 20 "The coefficient of " }{XPPEDIT 18 0 "1/ z" "6#*&\"\"\"F$%\"zG!\"\"" }{TEXT 266 6 " is " }{XPPEDIT 18 0 "2" " 6#\"\"#" }{TEXT 267 21 " so the residue is " }{XPPEDIT 18 0 "`Res[f, 0]` = 2" "6#/%)Res[f,0]G\"\"#" }{TEXT 268 2 " ." }}}{EXCHG {PARA 0 "" 0 "" {TEXT 278 1 "\n" }{TEXT 256 22 "Example 8.2, Page 308." }{TEXT 282 23 " Find the residue at " }{XPPEDIT 18 0 "z = 0" "6#/%\"zG\"\"! " }{TEXT 269 20 " for the function " }{XPPEDIT 18 0 "g(z) = 3/(2*z + z^2 - z^3)" "6#/-%\"gG6#%\"zG*&\"\"$\"\"\",(*&\"\"#F*F'F*F**$F'F-F**$ F'F)!\"\"F0" }{TEXT 261 3 " .\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 110 "g:='g': s:='s': z:='z':\ng := z -> 3/(2*z + z^2 - z^3):\ns := series( g(z), z=0, 5):\n`g(z) ` = g(z);\n`g(z) ` = s;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 262 20 "The coefficie nt of " }{XPPEDIT 18 0 "1/z" "6#*&\"\"\"F$%\"zG!\"\"" }{TEXT 270 6 " \+ is " }{XPPEDIT 18 0 "3/2" "6#*&\"\"$\"\"\"\"\"#!\"\"" }{TEXT 271 21 " so the residue is " }{XPPEDIT 18 0 "`Res[g,0]` = 3/2" "6#/%)Res[g, 0]G*&\"\"$\"\"\"\"\"#!\"\"" }{TEXT 272 75 " .\nWe compare this with Ma ple's residue procedure for computing residues.\n" }}{PARA 0 "> " 0 " " {MPLTEXT 1 0 62 "`g(z) ` = g(z);\n`g(z) ` = s;\n`Res[g,0] ` = residu e(g(z), z=0);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 256 22 "Example 8.3, Page 308." }{TEXT 283 30 " \+ Use residues to integrate " }{XPPEDIT 18 0 "int(exp(2/z), z=C..` \+ `)" "6#-%$intG6$-%$expG6#*&\"\"#\"\"\"%\"zG!\"\"/F,;%\"CG%$~~~G" } {TEXT 273 11 " around " }{XPPEDIT 18 0 "C" "6#%\"CG" }{TEXT 274 2 " : " }{XPPEDIT 18 0 "abs(z) = 1" "6#/-%$absG6#%\"zG\"\"\"" }{TEXT 275 21 " .\nFrom Example 8.1 " }{XPPEDIT 18 0 "`Res[f,0]` = 2" "6#/%)Res[ f,0]G\"\"#" }{TEXT 276 40 " . Thus the value of the integral is " } {XPPEDIT 18 0 "2*pi*i*`Res[f,0]`" "6#**\"\"#\"\"\"%#piGF%%\"iGF%%)Res[ f,0]GF%" }{TEXT 277 3 " .\n" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 218 "f:= 'f': F:='F': s:='s': z:='z':\nf := z -> exp(2/z):\n`F(z) ` = f(z);\ns \+ := series(f(z), z=infinity, 5):\nres := 2:\n`Res[F,0] ` = res; \nprin t(int(F(z),z=C..``) = `2*Pi*I*Res[f,0])`);\nprint(int(F(z),z=C..``) = \+ 2*Pi*I*res);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 256 39 "Theorem 8.1 (Cauchy's Residue Theorem)" } {TEXT 301 2 " " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 5 "Let " }{XPPEDIT 18 0 "D;" "6#%\"DG" }{TEXT -1 40 " be a \+ simply connected domain and let " }{XPPEDIT 18 0 "C;" "6#%\"CG" } {TEXT -1 63 " be a simple closed positively oriented contour that lie s in " }{XPPEDIT 18 0 "D" "6#%\"DG" }{TEXT -1 3 ". " }}{PARA 0 "" 0 "" {TEXT -1 4 "If " }{XPPEDIT 18 0 "f;" "6#%\"fG" }{TEXT -1 21 " is \+ analytic inside " }{XPPEDIT 18 0 "C" "6#%\"CG" }{TEXT -1 8 " and on " }{XPPEDIT 18 0 "C" "6#%\"CG" }{TEXT -1 24 ", except at the points " } {XPPEDIT 18 0 "z[1]" "6#&%\"zG6#\"\"\"" }{TEXT 303 3 " , " }{XPPEDIT 18 0 "z[2]" "6#&%\"zG6#\"\"#" }{TEXT 304 8 " , ..., " }{XPPEDIT 18 0 " z[n];" "6#&%\"zG6#%\"nG" }{TEXT -1 18 " that lie inside " }{XPPEDIT 18 0 "C" "6#%\"CG" }{TEXT -1 8 ", then " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 7 " " }{XPPEDIT 18 0 "Int(f(z),z = C .. ``);" "6#-%$IntG6$-%\"fG6#%\"zG/F);%\"CG%!G" }{TEXT -1 5 " = \+ " }{XPPEDIT 18 0 "2*pi*i" "6#*(\"\"#\"\"\"%#piGF%%\"iGF%" }{XPPEDIT 18 0 "Sum(`Res[ f , `*z[k]*`]`,k = 1 .. n);" "6#-%$SumG6$*(%*Res[~f~,~ G\"\"\"&%\"zG6#%\"kGF(%\"]GF(/F,;F(%\"nG" }{TEXT -1 10 " . " } {TEXT 302 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT 263 19 "End of Section 8.1." }}}}{MARK "0 0 0" 1 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }