{VERSION 5 0 "APPLE_PPC_MAC" "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 }{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 }} {SECT 0 {EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 55 " second-order ODE: y'' + ay' + by = cubic polynomial" }} {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 32 "clear workspace & load ODE stuff" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 8 "restart:" }}}{EXCHG {PARA 0 " > " 0 "" {MPLTEXT 1 0 14 "with(DEtools):" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 17 "define polynomial" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 33 "P := a3*t^3 + a2*t^2 + a1*t \+ + a0;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 20 "define solution form" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 33 "Y := c3*t^3 + c2*t^2 + c1*t + c0;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 19 "substitute into ODE" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 52 "ode := collect(diff(Y,t,t) + a*(diff(Y,t)) + b*Y,t); " }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 35 "solve for undetermined coefficients" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 45 "co := solve(identity(ode=P,t),\{c3,c2,c1,c0\});" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 23 "part_sol := subs(co,Y);" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 5 "voi la" }}}}{MARK "2 0 0" 8 }{VIEWOPTS 1 1 0 3 2 1804 1 1 1 1 } {PAGENUMBERS 0 1 2 33 1 1 }