{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 "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 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 261 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 262 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 263 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 264 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 265 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 266 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 267 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 268 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 269 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 270 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 271 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 272 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 273 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 274 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 275 "" 0 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 276 "" 0 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 277 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 278 "" 0 10 0 0 0 0 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 "" 0 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 281 "" 1 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 282 "" 0 10 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "G eneva" 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 0" -1 257 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 }{PSTYLE "R3 Font 2" -1 258 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 }} {SECT 0 {EXCHG {PARA 257 "" 0 "" {TEXT 257 41 "COMPLEX ANALYSIS: Maple Worksheets, 2001" }{TEXT 266 144 "\n(c) John H. Mathews Rus sell W. Howell\nmathews@fullerton.edu howell@westmont.edu\n\nCompl imentary software to accompany the textbook:" }}{PARA 257 "" 0 "" {TEXT 257 82 "COMPLEX ANALYSIS: for Mathematics & Engineering, 4th Ed, 2001, ISBN: 0-7637-1425-9" }{TEXT 265 197 "\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 269 1 "\n" }{TEXT 256 30 "CHAPTER 6 COMPLEX INTEGRATION" }{TEXT 267 2 "\n\n" }{TEXT 256 71 "Section 6.6 The Theorems of Morera and Liouvi lle and Some Applications" }{TEXT 268 1 "\n" }{TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 246 " In this section we investigate some of the qua litative properties of analytic and harmonic functions. Our first resu lt shows that the existence of an antiderivative for a continuous func tion is equivalent to the statement that the integral of " }{XPPEDIT 18 0 "f;" "6#%\"fG" }{TEXT -1 138 " is independent of the path of int egration. This result is stated in a form that will serve as a convers e to the Cauchy-Goursat theorem. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 30 "Theorem 6.13 (Morera Theorem)" }{TEXT -1 8 " Let " } {XPPEDIT 18 0 "f(z);" "6#-%\"fG6#%\"zG" }{TEXT -1 61 " be a continuou s function in a simply connected domain D. " }}{PARA 0 "" 0 "" {TEXT -1 5 "If " }{XPPEDIT 18 0 "int(f(z),z = C .. ` `) = 0;" "6#/-% $intG6$-%\"fG6#%\"zG/F*;%\"CG%\"~G\"\"!" }{TEXT -1 42 " for every cl osed contour in D, then " }{XPPEDIT 18 0 "f(z)" "6#-%\"fG6#%\"zG" } {TEXT -1 22 " is analytic in D. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 48 " Cauchy's integral formula sho ws how the value " }{XPPEDIT 18 0 "f(z[0])" "6#-%\"fG6#&%\"zG6#\"\"!" }{TEXT -1 91 " can be represented by a certain contour integral. If we choose the contour of integration " }{XPPEDIT 18 0 "C;" "6#%\"CG" } {TEXT -1 28 " to be a circle with center " }{XPPEDIT 18 0 "z[0]" "6#&% \"zG6#\"\"!" }{TEXT -1 34 ", then we can show that the value " } {XPPEDIT 18 0 "f(z[0])" "6#-%\"fG6#&%\"zG6#\"\"!" }{TEXT -1 43 " is th e integral average of the values of " }{XPPEDIT 18 0 "f(z)" "6#-%\"fG 6#%\"zG" }{TEXT -1 11 " at points " }{XPPEDIT 18 0 "z;" "6#%\"zG" } {TEXT -1 15 " on the circle " }{XPPEDIT 18 0 "C" "6#%\"CG" }{TEXT -1 3 ". " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 42 "Theorem 6.14 (Gauss's Mean Value Theorem)" }{TEXT -1 4 " " }}{PARA 0 "" 0 "" {TEXT -1 4 "If " }{XPPEDIT 18 0 "f(z" "6#-% \"fG6#%\"zG" }{TEXT -1 76 " is analytic in a simply connected domain \+ D that contains the circle C: " }{XPPEDIT 18 0 "abs(z-z[0]) = R" "6 #/-%$absG6#,&%\"zG\"\"\"&F(6#\"\"!!\"\"%\"RG" }{TEXT -1 9 " , then\n " }}{PARA 0 "" 0 "" {TEXT -1 5 " " }{XPPEDIT 18 0 "f(z[0])" "6#-% \"fG6#&%\"zG6#\"\"!" }{TEXT -1 6 " = " }{XPPEDIT 18 0 "1/(2*pi);" " 6#*&\"\"\"F$*&\"\"#F$%#piGF$!\"\"" }{TEXT -1 1 " " }{XPPEDIT 18 0 "int (f(z[0]+R*exp(i*theta)),theta = 0 .. 2*pi)" "6#-%$intG6$-%\"fG6#,&&%\" zG6#\"\"!\"\"\"*&%\"RGF.-%$expG6#*&%\"iGF.%&thetaGF.F.F./F6;F-*&\"\"#F .%#piGF." }{TEXT -1 7 " . " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 " " }}{PARA 0 "" 0 "" {TEXT 256 41 "Theorem 6.15 (Maximum Modulus Princ iple)" }{TEXT -1 3 " " }}{PARA 0 "" 0 "" {TEXT -1 5 "Let " } {XPPEDIT 18 0 "f(z)" "6#-%\"fG6#%\"zG" }{TEXT -1 55 " be analytic and nonconstant in the domain D. Then " }{XPPEDIT 18 0 "abs(f(z))" "6# -%$absG6#-%\"fG6#%\"zG" }{TEXT -1 48 " does not attain a maximum valu e at any point " }{XPPEDIT 18 0 "z[0]" "6#&%\"zG6#\"\"!" }{TEXT -1 10 " in D. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 71 "We sometimes st ate the maximum modulus principle in the following form." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 41 "Theorem \+ 6.16 (Maximum Modulus Principle)" }{TEXT -1 3 " " }}{PARA 0 "" 0 " " {TEXT -1 4 "Let " }{XPPEDIT 18 0 "f(z)" "6#-%\"fG6#%\"zG" }{TEXT -1 58 " be analytic and nonconstant in the bounded domain D. If " } {XPPEDIT 18 0 "f;" "6#%\"fG" }{TEXT -1 36 " is continuous on the close d region " }{XPPEDIT 18 0 "R;" "6#%\"RG" }{TEXT -1 51 " that consists \+ of D and all of its boundary points " }{XPPEDIT 18 0 "B;" "6#%\"BG" } {TEXT -1 8 ", then " }{XPPEDIT 18 0 "abs(f(z))" "6#-%$absG6#-%\"fG6#% \"zG" }{TEXT -1 59 " assumes its maximum value, and does so only at p oint(s) " }{XPPEDIT 18 0 "z[0]" "6#&%\"zG6#\"\"!" }{TEXT -1 17 " on t he boundary " }{XPPEDIT 18 0 "B" "6#%\"BG" }{TEXT -1 1 "." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 37 "Theorem \+ 6.17 (Cauchy's Inequalities)" }{TEXT -1 3 " " }}{PARA 0 "" 0 "" {TEXT -1 5 "Let " }{XPPEDIT 18 0 "f(z)" "6#-%\"fG6#%\"zG" }{TEXT -1 77 " be analytic and nonconstant in the domain D that contains the \+ circle C: " }{XPPEDIT 18 0 "abs(z-z[0]) = R" "6#/-%$absG6#,&%\"zG\"\" \"&F(6#\"\"!!\"\"%\"RG" }{TEXT -1 4 " . " }}{PARA 0 "" 0 "" {TEXT -1 4 "If " }{XPPEDIT 18 0 "abs(f(z)) < M" "6#2-%$absG6#-%\"fG6#%\"zG%\"M G" }{TEXT -1 36 " holds for all points z on C, then " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 7 " " }{XPPEDIT 18 0 "abs(f^`(n)`*`(`*z[0]*`)`) <= n!*M/R^n" "6#1-%$absG6#**)%\"fG%$(n)G \"\"\"%\"(GF+&%\"zG6#\"\"!F+%\")GF+*(-%*factorialG6#%\"nGF+%\"MGF+)%\" RGF6!\"\"" }{TEXT -1 11 " for " }{XPPEDIT 18 0 "n=1,2,`...`" "6% /%\"nG\"\"\"\"\"#%$...G" }{TEXT -1 4 " . " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 90 " The next result shows t hat a nonconstant entire function cannot be a bounded function. " }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 36 "T heorem 6.18, (Liouville's Theorem)" }{TEXT 274 3 " " }}{PARA 0 "" 0 "" {TEXT 275 4 "If " }{XPPEDIT 18 0 "f(z)" "6#-%\"fG6#%\"zG" } {TEXT 273 1 " " }{TEXT 276 27 " is an entire function and " }{TEXT 277 1 " " }{XPPEDIT 18 0 "f(z)" "6#-%\"fG6#%\"zG" }{TEXT 270 2 " " } {TEXT 280 28 "is bounded for all values of" }{TEXT 281 2 " " } {XPPEDIT 18 0 "z" "6#%\"zG" }{TEXT 271 1 " " }{TEXT 278 28 " in the co mplex plane, then " }{TEXT 279 1 " " }{XPPEDIT 18 0 "f(z)" "6#-%\"fG6# %\"zG" }{TEXT 272 2 " " }{TEXT 282 13 "is constant. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 257 "" 0 "" {TEXT 263 1 "\n" }{TEXT 256 23 "Example 6.27, Page 256." }{TEXT 262 26 " Show tha t the function " }{XPPEDIT 18 0 "sin(z" "6#-%$sinG6#%\"zG" }{TEXT 261 5 " is " }{TEXT 257 3 "NOT" }{TEXT 264 21 " a bounded function.\n " }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 299 "i:='i': x:='x': y:='y': z:='z' :\nf := z -> sin(z):\n`f(z) ` = f(z);\n`f(x + iy) ` = f(x + I*y);\n`f( x + iy) ` = evalc(f(x + I*y));\n`|f(x + iy)| ` = evalc(abs(f(x + I*y)) );\nf(pi/2 + i*y) = evalc(f(Pi/2 + I*y));\nlim := limit(f(Pi/2 + I*y), y=infinity):\nprint(`limit(f(pi/2 + I*y), y=infinity)`,` = `,lim);" } }}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 101 "We can use Liouville's theorem can be used to establish an important \+ theorem of elementary algebra. " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 256 50 "Theorem 6.19 (The Fundamental Theorem of Algebra)" }{TEXT -1 4 " " }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 4 "If " }{XPPEDIT 18 0 "P(z)" "6#-%\"PG6#%\"zG" }{TEXT -1 39 " is a po lynomial of degree n, then " }{XPPEDIT 18 0 "P(z)" "6#-%\"PG6#%\"zG " }{TEXT -1 24 " has at least one zero." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 " " {TEXT 256 13 "Corollary 6.4" }{TEXT -1 8 " Let " }{XPPEDIT 18 0 " P(z)" "6#-%\"PG6#%\"zG" }{TEXT -1 39 " be a polynomial of degree n. \+ Then " }{XPPEDIT 18 0 "P(z)" "6#-%\"PG6#%\"zG" }{TEXT -1 64 " can b e expressed as the product of linear factors. That is, " }{XPPEDIT 18 0 "P(z) = A*(z - z[1])*`...`*(z - z[2])*(z - z[n])" "6#/-%\"PG6#%\" zG*,%\"AG\"\"\",&F'F*&F'6#F*!\"\"F*%$...GF*,&F'F*&F'6#\"\"#F.F*,&F'F*& F'6#%\"nGF.F*" }{TEXT -1 9 " where " }{XPPEDIT 18 0 "z[1],z[2],`...` ,z[n]" "6&&%\"zG6#\"\"\"&F$6#\"\"#%$...G&F$6#%\"nG" }{TEXT -1 20 " ar e the zeros of " }{XPPEDIT 18 0 "P(z)" "6#-%\"PG6#%\"zG" }{TEXT -1 57 " counted according to multiplicity an A is a constant." }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 257 "" 0 "" {TEXT 260 19 "End of Section 6.6." }}}}{MARK "0 0 0" 11 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }