{VERSION 4 0 "IBM INTEL NT" "4.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 1 }{CSTYLE "" -1 256 "" 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 } {CSTYLE "" -1 257 "" 0 1 0 0 0 0 1 1 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 258 "" 1 14 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 259 "" 1 14 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 260 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 261 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 } {CSTYLE "" -1 262 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 263 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 271 "" 0 1 0 0 0 0 1 1 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 278 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 279 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 } {CSTYLE "" -1 280 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 281 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 282 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 283 "" 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 286 "" 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 }{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 }{PSTYLE "Normal" -1 256 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }3 1 0 0 0 0 1 0 1 0 2 2 0 1 }} {SECT 0 {EXCHG {PARA 256 "" 0 "" {TEXT -1 0 "" }}{PARA 256 "" 0 "" {TEXT 256 48 "MAT1154 - Equa\347\365es Diferenciais e de Diferen\347as " }}{PARA 256 "" 0 "" {TEXT 257 19 "Ass\355ntota vertical." }}{PARA 256 "" 0 "" {TEXT -1 3 "por" }}{PARA 256 "" 0 "" {TEXT -1 17 "George S vetlichny" }}{PARA 256 "" 0 "" {TEXT 258 57 "\005\005\005M\311TODOS NU M\311RICOS DE SOLU\307\303O DE ODE DE \010PRIMEIRA ORDEM" }}{PARA 256 "" 0 "" {TEXT 259 69 "Baseado nos scripts do site da Maplesoft e adapt a\347\365es do Prof. Grivet" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 38 "restart:with( DEtools ):with ( plots ):" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 9 "A e.d.o. " }{TEXT 261 8 "y'=y^2+t" }{TEXT -1 26 " demonstra o fen\364mento de " }{TEXT 260 15 "instabilidade. " }{TEXT -1 34 "Definimos primeiro o lado direi to:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 14 "fun:=y(t)^2+t;" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 26 "Definimos agora a equa\347\343o." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 16 "eq:=D(y)(t)=fun;" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 24 "Achamos a solu\347\343o geral." }} }{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 21 "sol:=dsolve(eq,y(t));" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 66 "A solu\347\343o geral \351 express a por meio das fun\347\365es especiais de Airy." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 33 "Definimos uma condi\347\343o inical em " }{TEXT 262 5 "y(0)." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 11 "ci:=y(0)=0;" }} }{EXCHG {PARA 0 "" 0 "" {TEXT -1 42 "Resolvemos agora com esta condi \347\343o inical:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 27 "sola:= dsolve([eq,ci],y(t));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 25 "Pegamos \+ a fun\347\343o solu\347\343o:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 24 "funsol:=subs(sola,y(t));" }{TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 26 "Plotamos agora a solu\347\343o " }{TEXT 271 5 "exata " }{TEXT -1 14 " no intervalo " }{TEXT 288 5 "[0,3]" }{TEXT -1 2 ".." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 43 "plot(funsol,t=0..3,y=-10. .10, colour=blue);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 50 "Note que h \341 uma ass\355ntota vertical perto do valor " }{TEXT 289 4 "t=2." }} }{EXCHG {PARA 0 "" 0 "" {TEXT -1 128 "Vamos resolver agora a mesma equ a\347\343o numericamente usando o m\351todo de Euler. Definimos o proc edimento de Euler. Nesta defini\347\343o " }{TEXT 278 1 "f" }{TEXT -1 31 " \351 a fun\347\343o do lado direito de " }{TEXT 279 9 "y'=f(t,y) " }{TEXT -1 2 ", " }{TEXT 280 8 "(t0,y0) " }{TEXT -1 22 "\351 a condi \347\343o inicial, " }{TEXT 281 1 "h" }{TEXT -1 25 " \351 o tamanho do passo, e " }{TEXT 282 1 "T" }{TEXT -1 5 " (> " }{TEXT 283 3 "t0)" } {TEXT -1 65 " \351 o ponto final do intervalo onde procuramos a solu \347\343o n\372merica." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 32 "E uler := proc( f, t0, y0, h, T )" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 39 " local i, L, X ,N; N:=round((T-t0)/h);" }{TEXT -1 1 " " }}{PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 27 " X := evalf( [ t0, y0 ] );" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 9 " L := X;" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 22 " f or i from 1 to N do" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 31 " X := X + [ h, h*f(op(X)) ];" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 14 " L := L, \+ X;" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 9 " end do;" }}{PARA 0 "> " 0 " " {MPLTEXT 1 0 11 " return L;" }}{PARA 0 "" 0 "" {TEXT -1 0 "" } {MPLTEXT 1 0 9 "end proc;" }{TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 19 "Definimos a fun\347\343o " }{TEXT 263 6 "y^2+t:" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 19 "func:=(t,y)->y^2+t;" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 61 "Chamamos agora o Euler com a mesma condi\347\365es iniciais, usand " }{TEXT 286 5 "h=0,3" }{TEXT -1 17 " e ponto final 3." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "aa:=Eu ler(func,0,0,0.3,3);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 90 "Plotamos \+ a solu\347\343o exata (em azul) junto com o resultado do met\363do num \351rico (em vermelho)." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 54 " plot([[aa],funsol],t=0..3,y=-5..20,colour=[red,blue]);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 77 "Note que o m\351todo num\351rico simples \+ n\343o soube lidar com a ass\355ntota vertical. " }}}}{MARK "27" 0 } {VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }