{VERSION 4 0 "IBM INTEL NT" "4.0" } {USTYLETAB {CSTYLE "" -1 256 "" 1 14 0 0 0 0 0 1 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 257 "" 0 1 0 0 0 0 0 2 0 0 0 0 0 0 0 0 }{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 }} {SECT 0 {EXCHG {PARA 256 "" 0 "" {TEXT 256 0 "" }{TEXT -1 54 "PHYS 312 :\nSOLUTIONS TO PROBLEMS\nSect 5.6\nProblem 5.6:1" }}{PARA 256 "" 0 " " {TEXT 257 518 "The infinite series representation for the Bessel fun ction is\n\\[J_n(x)=(\\frac\{x\}\{2\})^n\\sum_\{m=0\}^\{\\infty\}\\fra c\{(-1)^m(\\frac\{x\}\{2\})^\{2m\}\}\{m!(n+m)!\}\\]\nHence\n\\[\\frac \{d\}\{dx\}(x^\{-n\}J_n(x))=(\\frac\{1\}\{2\})^n\\sum_\{m=1\}^\\infty \n\\frac\{(-1)^m(\\frac\{x\}\{2\})^\{2m-1\}\}\{(m-1)!(n+m)!\}\\]\nWe p ut $k=m-1$\n\\[\\frac\{d\}\{dx\}(x^\{-n\}J_n(x))=-x^\{-n\}(\\frac\{x\} \{2\})^n\\sum_\{k=0\}^\\infty\n\\frac\{\\frac\{x\}\{2\}(\\frac\{x\}\{2 \})^\{2k\}(-1)^k\}\{k!(n+1+k)!\}\\]\n\\[=-x^\{-n\}(\\frac\{x\}\{2\})^ \{n+1\}\\sum_\{k=0\}^\\infty\\frac\{(-1)^k(\\frac\{x\}\{2\})^\{2k\}\} \{k!(n+1+k)!\}=-x^\{-n\}J_\{n+1\}(x)\\]\n" }{TEXT -1 1 "\n" }}}}{MARK "0 0 1" 52 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }