{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 }{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 "Title " -1 18 1 {CSTYLE "" -1 -1 "Times" 1 18 0 0 0 1 2 1 1 2 2 2 1 1 1 1 } 3 1 0 0 12 12 1 0 1 0 2 2 19 1 }} {SECT 0 {EXCHG {PARA 18 "" 0 "" {TEXT -1 36 "Direction Fields and Syst ems of ODEs" }}}{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 30 "Define the system of equations" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 60 "odes := diff(x(t),t)=2*x(t)- y(t),diff(y(t),t)=3*x(t)-2*y(t);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 68 "Generate a direction field along with a specific solution trajecto ry" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 124 "DEplot([odes],\n[x(t ),y(t)],t=0..3.8,[ [x(0)=0.5,y(0)=2]],x=-3..3,y=-3..3,arrows=SLIM,\nti tle=`Linear System`,linecolor=blue);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 30 "Construct the general solution" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 27 "dsolve(\{odes\},[x(t),y(t)]);" }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 24 "ics := x(0)=0.5, y(0)=2;" }}}{EXCHG {PARA 0 " " 0 "" {TEXT -1 44 "Solve initial value problem using above ICS." }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 31 "dsolve(\{odes,ics\},[x(t),y( t)]);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 51 "Set up a procedure to so lve the system numerically." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 65 "dsolve(\{odes,ics\},\{x(t),y(t)\},type=numeric,output=listprocedur e);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 62 "Define the solution as fun ctions X(t) and Y(t) - a Maple trick" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 38 "X := subs(%,x(t)); Y := subs(%%,y(t));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 58 "Xplot := plot( X,0..2,color=blue): \+ Yplot := plot( Y,0..2):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 30 " plots[display](\{Xplot,Yplot\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 5 "X(1);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" } }}}{MARK "20" 0 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }