{VERSION 3 0 "IBM INTEL NT" "3.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Text Output " -1 2 1 {CSTYLE "" -1 -1 "Courier" 1 10 0 0 255 1 0 0 0 0 0 1 3 0 3 } 1 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Warning" 2 7 1 {CSTYLE "" -1 -1 "" 0 1 0 0 255 1 0 0 0 0 0 0 1 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Maple Output" 0 11 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 3 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 256 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 257 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 258 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "" 0 259 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }} {SECT 0 {EXCHG {PARA 0 "" 0 "" {TEXT -1 33 "Local Stability worked exa mple 2." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 43 "Find the equilibria of the nonlinear syst em" }}{PARA 256 "" 0 "" {OLE 1 4109 1 "[xm]Br=WfoRrB:::wk;nyyI;G:;:j:: >:B>N:F:nyyyyy]::yyyyyy::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::::::::::fyyyyya:nYf::G:jy;:::::::::::::::::::::::::::: :::::::::::::::::::::::::::::::::::::::::::::::::::JcvGYMt>^:fBWMtNHm= ;:::::::n:;JZC:bKB::>vuidO?bJoq;V:>Z?>Z:B:F:YLpfF>:::::: :::J?NZ;vyyyyyY:vYxY:B:::::::c:;:=:jR>@Wlj^HMMufF;J:::::::N=?:xI:;Z::: :::j:>:[^::=j[vGUMrvC?MoJ::::::::JCN:yyyxI:;Z::::::j;B:s<;:wA?Z:F;^:nY n:v:J?>:wAQB:^;f;;JA>:YJ:>\\:B:]:_J:VAFX_rZmm:Dm;aQ=D:N\\=Hi=b:KvFB::;:::::=Jyyy;d:yayY;A:;JZ?Z:Z @O<;j`@Pt\\Pd`QrPPJPnrPqjLqnxPqF;fbk;::JtaMSAQ:>Z::::::::jysyA:CB:F:;j ysy?:;:OF=Nt>JKH:=j>r:]N:N:e:;jD:Z:^:n_;>=E :]c:=Z:f:V[f>>fEn;n^@v;_jysy;B:KJ:>ryIsyA^EF_>V;n>^;UTRZ_?:;q @[;;B:::::::JFNZ;J:N:;B:yayA:;B::::::f:D_=a=[;;B:::::::JF>:yay=J:B::::::nYyA<::::::::::::jysy:>:<::::::::::: ::::::::vYxI:;Z:::::::::]:qi:;fy>Z:JBAJ:UDO;SKkEW_URDMJMJNTM;_;s]=OJH>f<l;F: >Z^:f?=J:m=JSjiMj:>:kE:N;N@nZAN:;Jv`AF;N@FvCF:;jvJBB :qAB:>l;>:DZaTXDpql`O^Z:jP>:C:[q:F;;JSdje^e;FZ:>Z:fAap>JSJCEj:>:UC: a@N@QPn@j:jX:N@Np=F:;jP:N@>u?F:V?a@N@>oBF:;jPjDjw;<:[V:B:D:cTTP@:JF^Z: jP@j:^:>X;j>>:_keff=FZ:B:l;Z:b::::u;f?;JHO:Gc;N;yyyxy:J:><:sg:B:=b:?bBaTXaEWEUUtP:::::::::::::::::::::::::::::::::::::::::::::::::4:" } {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 30 "and determine the ir stability." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 34 "First find the equilibrium points." }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 8 "restart:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "with(linalg):" }}{PARA 7 "" 1 "" {TEXT -1 32 "Warning, new def inition for norm" }}{PARA 7 "" 1 "" {TEXT -1 33 "Warning, new definiti on for trace" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 14 "with(DEtool s):" }}{PARA 7 "" 1 "" {TEXT -1 35 "Warning, new definition for adjoin t" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 10 "f:=-2*x*y;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "g:=y-x+x*y-y^3;" }{TEXT -1 0 "" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 23 "solve(\{f=0,g=0\},\{x,y\}); " }}{PARA 11 "" 1 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 48 "The equilibrium points are (0,0), (0,1), (0,-1)." }}{PARA 0 "" 0 " " {TEXT -1 78 "Note that the final bracket only gives the point (0,0) \+ which is already given." }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 27 "To fin d the Jacobian matrix" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 10 "f: =-2*x*y;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "g:=y-x+x*y-y^3; " }{TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 9 "v:=[f,g]; " }{TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 21 "J:=jacob ian(v,[x,y]);" }}{PARA 11 "" 1 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 18 "At the point (0,0)" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 29 "J0:=subs(\{x=0,y=0\},evalm(J));" }}{PARA 11 "" 1 "" {TEXT -1 0 "" }}}{EXCHG {PARA 257 "" 0 "" {OLE 1 4105 1 "[xm]Br=WfoRrB :::wk;nyyI;G:;:j::>:B>N:F:nyyyyy]::yyyyyy::::::::::::::::::::::::::::: ::::::::::::::::::::::::::::::::::::::::::fyyyyya:nYf::G:jy;:::::::::: :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::J cvGYMt>^:fBWMtNHm=;:::::::n:;JZC:bKB::>n]veO?bJoq;V:>r>Z :j:vCSmlJ::::::::::OJ;@jyyyyyy;jysy;Z:::::::^<>:F::]KRnC=MtFGgml>:;::: :::JGN:ry:>:<::::::=J:^J>:F:AlqfG[maNFO=;::::::::_J;vyyuy:>:<::::::AZ: ^E>:nYN:J:W:YJ:>\\:B:]:_J:nYvY::::::::::::: :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::F:DZ:B::::: :::::>JkkNZ<`_d:Xb[og]gffk=v:;J:::::j:Z::::::::jysyA:CB:F:;jy sy?:;:Er=Vi:EB:;j>D:JZyYZyYjpZ^;UTR:;JjZ:F;NZ:vCS=[LsfFaMR>@>Z::::::::kJ;@:;J;>Z:vYxY:>Z::::::j D_=a=[;;B:::::::JF>:yay=J:B::::::nYyA<::::::::::::jysy:>:<:::::::::::: :::::::vYxI:;Z:::::::::eZ:Vy<>jx]:JBAj:J:DZJ^dcgg_WhZnc_whZNdigg[oGCK< jP@:OZ:N`D>j;^@?J:>:::::::::::^hlWGen>>Z:N@nw;F:Uj;JlPPt> ROooF;N@n]CF:NCf:_;;p:RM:_;AU ;=:]C:;@N@>xCF:X=j >>:_kFAj\\@j:>Z:NFwm>JSNm;Vi=F:;jmnIJSFMeE<=:?=JSNMQg<=:I=[Z:VY;><:[V: b:DZJVdscRYEU\\KF:;B:ukcG;N@fiEF:fAf:sg:>Z:F:?bBa TXaEWEUUtP " 0 "" {MPLTEXT 1 0 23 "A:=diff(x(t),t) =-2*x*y;" }}{PARA 11 "" 1 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 28 "B:=diff(y(t),t)=y-x+x*y-y^3;" }}{PARA 11 "" 1 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 118 "DEplot(\{A,B\},\{x(t),y(t)\},-50..50,[[0,1 ,1],[0,-.1,.1],[0,0.1,-0.1],[0,-0.1,-0.1]],x=-0.5..0.5,y=-0.5..0.5,ste psize=.1);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 86 "The phase portrait \+ suggests the equilibrium point of the nonlinear system is unstable." } }{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 18 " At the point (0,1)" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 29 "J1:=s ubs(\{x=0,y=1\},evalm(J));" }}{PARA 11 "" 1 "" {TEXT -1 0 "" }}} {EXCHG {PARA 258 "" 0 "" {TEXT -1 1 " " }{OLE 1 4617 1 "[xm]Br=WfoRrB: ::wk;nyyI;G:;:j::>:B>N:F:nyyyyy]::yyyyyy:::::::::::::::::::::::::::::: :::::::::::::::::::::::::::::::::::::::::fyyyyya:nYf::G:I:wAyA:::::::: :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: :NDYmq^H;C:ELq^H_mvJ::::::::gjR<:T><::;wByTO;DNwW:A:;f ;B:F:YLpfF>:::::::::J?NZ;vyyyyyY:vYxY:B:::::::c:;:=:jR>@Wlj^HMMufF;J:: :::::N=?:xI:;Z::::::j:>:CA;:=j[vGUMrvC?MoJ::::::::JCN:yyyxI:;Z::::::j; 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