{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 }} {SECT 0 {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 149 "# Method of undeter mined coefficients to get a\n# particular solution to non-homogeneous \+ linear\n# equations\n\n# filename = 04.4.mws\n\nrestart;\n\n?DEtools" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 9 "Example 1" }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 64 "Hom_Sol:=dsolve(diff(y(x),x$2)+5*diff(y(x),x)+ 6*y(x)=0,\n\011\011y(x));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 16 "yp:=x->A*exp(x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 48 "LHS eqn:=diff(yp(x),x$2)+5*diff(yp(x),x)+6*yp(x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 43 "match(2*exp(x)=12*A*exp(x),x,'Val'):\n Val;" }} }{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 21 "assign(Val):\n yp(x);" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 71 "Gen_Sol:=dsolve(diff(y(x),x$ 2)+5*diff(y(x),x)+\n\011\0116*y(x)=2*exp(x),y(x));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 89 "to_plot:=[seq(seq(rhs(Gen_Sol),\n\011_C1=-1 ..1),_C2=-1..1)]:\n plot(to_plot,x=-3..5,y=-3..5);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 40 "A:='A':yp:='yp':\n yp:=x->A*x*exp(-2*x): " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "Diff(yp(x),x)=diff(yp(x ),x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 32 "Diff(yp(x),x$2)=di ff(yp(x),x$2);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 57 "eqn:=diff (yp(x),x$2)+5*diff(yp(x),x)+6*yp(x)=3*exp(-2*x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 19 "aval:=solve(eqn,A);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 103 "y:='y':\n part_sol:=dsolve(\{diff(y(x),x$2)+5* diff(y(x),x)+\n\0116*y(x)=3*exp(-2*x),y(0)=a,D(y)(0)=b\},y(x));" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 81 "to_plot:=[seq(seq(rhs(part_s ol),\n\011a=0..2),b=-1..1)]:\n plot(to_plot,x=-1/2..3/2);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 9 "Example 2" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 92 "y:='y':\n Hom_sol:=dsolve(diff(y(x),x$3)+4*diff(y(x) ,x$2)+\n\01114*diff(y(x),x)+20*y(x)=0,y(x));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 79 "A:='A':B:='B':C:='C':\n yp:=x->A*x*exp(-2*x)+x* exp(-x)*(B*cos(3*x)+C*sin(3*x)):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 110 "eqn:=simplify(diff(yp(x),x$3)+4*diff(yp(x),x$2)+\n \01114*diff(yp(x),x)+20*yp(x))=10*exp(-2*x)-\n\011\011exp(-x)*cos(3*x) ;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "eqn1:=eval(subs(x=0,eq n));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 29 "eqn2:=eval(subs(x=P i/6,eqn));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 29 "eqn3:=eval(su bs(x=Pi/3,eqn));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 32 "consts: =solve(\{eqn1,eqn2,eqn3\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 29 "Part_sol:=subs(consts,yp(x));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 25 "y:=rhs(Hom_sol)+Part_sol;" }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 25 "eq1:=eval(subs(x=0,y))=5;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 33 "eq2:=eval(subs(x=0,diff(y,x)))=0;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 38 "eq3:=eval(subs(x=0,diff(y,x$2)))=-1 /2;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "cvals:=solve(\{eq1,e q2,eq3\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 17 "assign(cvals) :\ny;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "plot(y,x=0..2);" } }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 122 "y:='y':\n Gen_Sol:=dsolv e(diff(y(x),x$3)+4*diff(y(x),x$2)+\n\01114*diff(y(x),x)+20*y(x)=\n\011 10*exp(-2*x)-exp(-x)*cos(3*x),y(x));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 22 "combine(Gen_Sol,trig);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 191 "y:='y':\n Init_Sol:=dsolve(\{diff(y(x),x$3)+4*diff( y(x),x$2)+\n\01114*diff(y(x),x)+20*y(x)=10*exp(-2*x)-exp(-x)*cos(3*x), \n\011y(0)=y0,D(y)(0)=y1,(D@@2)(y)(0)=y2\},y(x)):\nstep2:=combine(Init _Sol,trig);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 174 "assign(Init _Sol):\n y0_vals:=\{-1,2\}:y1_vals:=\{-3,0,3\}:y2_vals:=\{-2,2\}:\n \+ to_plot:=\{seq(seq(seq(rhs(step2),\n\011y0=y0_vals),y1=y1_vals),y2=y2_ vals)\}:\n plot(to_plot,x=-1/2..3/2);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 9 "Example 3" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 71 "y: ='y':\nhomsol:=dsolve(4*diff(y(x),x$2)+4*diff(y(x),x)+37*y(x)=0,y(x)); " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 44 "A:='A':B:='B':\nyp:=x-> A*cos(3*x)+B*sin(3*x):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 69 "s tep1:=simplify(4*diff(yp(x),x$2)+4*diff(yp(x),x)+37*yp(x))=cos(3*x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 27 "eq1:=eval(subs(x=0,step1) );" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 30 "eq2:=eval(subs(x=Pi/6 ,step1));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 23 "vals:=solve(\{ eq1,eq2\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 20 "assign(vals) :\nyp(x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 29 "y:='y':\ny:=rh s(homsol)+yp(x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 18 "eval(su bs(x=0,y));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 19 "eval(subs(x= Pi,y));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 50 "cval:=solve(eval (subs(x=0,y))=eval(subs(x=Pi,y)));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 22 "sol:=subs(_C4=cval,y);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 53 "toplot:=\{seq(sol,_C5=-5..5)\}:\nplot(toplot,x=0..2*P i);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 9 "Example 4" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 53 "x:='x':\nhomsol:=dsolve(diff(x(t),t$2)+4* x(t)=0,x(t));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 52 "A:='A':B:= 'B':\nxp:=t->A*cos(omega*t)+B*sin(omega*t):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 54 "step1:=simplify(diff(xp(t),t$2)+4*xp(t))=sin(omega *t);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "eqn1:=eval(subs(t=0 ,step1));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 39 "eqn2:=eval(sub s(t=Pi/(2*omega),step1));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 31 "vals:=solve(\{eqn1,eqn2\},\{A,B\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 43 "x:='x':\nassign(vals):\nx:=rhs(homsol)+xp(t);" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 74 "cvals:=solve(\{eval(subs(t=0 ,x))=1,eval(subs(t=0,diff(x,t)))=0\},\{_C4,_C5\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 20 "sola:=subs(cvals,x);" }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 99 "A:='A':B:='B':\nxp:=t->t*(A*cos(2*t)+B*sin(2*t )):\nstep1:=simplify(diff(xp(t),t$2)+4*xp(t))=sin(2*t);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "eqn1:=eval(subs(t=0,step1));" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 32 "eqn2:=eval(subs(t=Pi/12,step 1));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 25 "vals:=solve(\{eqn1, eqn2\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 35 "assign(vals):\n x:=rhs(homsol)+xp(t);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 74 "cv als:=solve(\{eval(subs(t=0,x))=1,eval(subs(t=0,diff(x,t)))=0\},\{_C4,_ C5\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 20 "solb:=subs(cvals, x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 88 "x:='x':t:='t':\nsolc :=dsolve(\{diff(x(t),t$2)+4*x(t)=sin(omega*t),x(0)=1,D(x)(0)=0\},x(t)) ;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "omegavals:=[seq(.9+.25 *i,i=0..8)]:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 90 "somegraphs: =[seq(plot(subs(omega=i,sola),t=0..18*Pi,x=-1..1,\n\011\011color=BLACK ),i=omegavals)]:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 80 "with(pl ots):\n anarray:=display(somegraphs,insequence=true):\n display(anar ray);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 22 "plot(solb,t=0..18* Pi);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 69 "sold:=dsolve(\{diff (x(t),t$2)+4*x(t)=sin(2*t),x(0)=1,D(x)(0)=0\},x(t));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 19 "combine(sold,trig);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{MARK "73 0 0" 19 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }