{VERSION 3 0 "SUN SPARC SOLARIS" "3.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 }{CSTYLE "2D Math" -1 2 "Times" 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 }{CSTYLE "2D Comment" 2 18 "" 0 1 0 0 0 0 0 0 0 0 0 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 }} {SECT 0 {EXCHG {PARA 0 "" 0 "" {TEXT -1 12 "White test 1" }}{PARA 0 " " 0 "" {TEXT -1 53 "1. a. linear, variable coerricients, nonhomogene ous" }}{PARA 0 "" 0 "" {TEXT -1 18 " b. same as a" }}{PARA 0 "" 0 "" {TEXT -1 34 " c. nonlinear because of the " }{XPPEDIT 18 0 " y^2" "6#*$%\"yG\"\"#" }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 2 "2. " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 97 "restart:d2:=t*diff(y(t) ,t,t)+(1-t)*diff(y(t),t)-y(t)=0;\nd2s:=simplify(subs(y(t)=u(t)*exp(t), d2));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 165 "### WARNING: `dso lve` has been extensively rewritten, many new result forms can occur a nd options are slightly different, see help page for details\ndsolve(d 2s,u(t));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 20 "ans2:=exp(t)*r hs(%);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 2 "3." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 61 "d3:=x^2*diff(y(x),x,x)-2*y(x)=0;\nsimplify(su bs(y(x)=x^2,d3));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "simpli fy(subs(y(x)=1/x,d3));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 46 "3 b. \+ Differentiate and sub x=1 in your head." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 30 "solve(\{a+b=1, 2*a-b=1\},\{a,b\});" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 2 "4." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 223 "### WARNING: `dsolve` has been extensively rewritten, many new re sult forms can occur and options are slightly different, see help page for details\ndsolve(\{diff(y(x),x,x)+2*diff(y(x),x)+10*y(x)=0, y(0)=0 , D(y)(0)=1\}, y(x));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 2 "5." }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 68 "d5:=diff(y(x),x,x,x)-3*diff( y(x),x,x)-diff(y(x),x)+3*y(x)=1+exp(-x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 36 "simplify(subs(y(x)=a+b*exp(-x),d5));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 23 "From this you see that " }{XPPEDIT 18 0 " x*exp(-x)" "6#*&%\"xG\"\"\"-%$expG6#,$F$!\"\"F%" }{TEXT -1 11 " is nee ded." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 38 "simplify(subs(y(x)= a+b*x*exp(-x),d5));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 4 "So, " } {XPPEDIT 18 0 "b=1/8" "6#/%\"bG*&\"\"\"\"\"\"\"\")!\"\"" }{TEXT -1 5 " and " }{XPPEDIT 18 0 "a=1/3" "6#/%\"aG*&\"\"\"\"\"\"\"\"$!\"\"" } {TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 54 "Sol5:=1/8*x*exp(-x)+1/3: simplify(subs(y(x)=Sol5 ,d5));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 17 "6. Using dsolve:" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 229 "s6:=\{diff(x(t),t)=2*x(t)-y (t), diff(y(t),t)=x(t)-2*y(t)\};\n### WARNING: `dsolve` has been exten sively rewritten, many new result forms can occur and options are slig htly different, see help page for details\ndsolve(s6,\{x(t),y(t)\});" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 49 "The laplace option gives a more compact solution!" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 179 "### \+ WARNING: `dsolve` has been extensively rewritten, many new result form s can occur and options are slightly different, see help page for deta ils\ndsolve(s6,\{x(t),y(t)\},laplace);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 50 "You can get the 2nd order de in your head (almost)" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 33 "diff(diff(x(t),t)=2*x(t)-y(t ),t);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "subs(diff(y(t),t)= x(t)-2*y(t), %);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 37 "d6:=sub s(y(t)=2*x(t)-diff(x(t),t),%);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 169 "### WARNING: `dsolve` has been extensively rewritten, many ne w result forms can occur and options are slightly different, see help \+ page for details\nsd6:=dsolve(d6,x(t));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 33 "y(t)=2*rhs(sd6)-diff(rhs(sd6),t);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 35 "A yellow test. Problem 1 a. is " }{XPPEDIT 18 0 "diff(y(t),t)=cos(t-y)" "6#/-%%diffG6$-%\"yG6#%\"tGF*-%$cosG6#,&F *\"\"\"F(!\"\"" }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 14 "1a. no nlinear" }}{PARA 0 "" 0 "" {TEXT -1 50 "1b. linear, variable coeffici ents, nonhomogeneous" }}{PARA 0 "" 0 "" {TEXT -1 30 "1c. nonlinear (be cause of the " }{XPPEDIT 18 0 "y^2" "6#*$%\"yG\"\"#" }{TEXT -1 1 ")" } }{PARA 0 "" 0 "" {TEXT -1 21 "2. Same as #2 above." }}{PARA 0 "" 0 " " {TEXT -1 20 "3. Same as #3 above" }}{PARA 0 "" 0 "" {TEXT -1 2 "4. " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 222 "### WARNING: `dsolve` \+ has been extensively rewritten, many new result forms can occur and op tions are slightly different, see help page for details\ndsolve(\{diff (y(x),x,x)+2*diff(y(x),x)+5*y(x)=0, y(0)=0, D(y)(0)=1\}, y(x));" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 105 "5. Either use dsolve (with the l aplace option) or do it by hand (notice that all you need is a functio n " }{XPPEDIT 18 0 "y" "6#%\"yG" }{TEXT -1 6 " with " }{XPPEDIT 18 0 " -diff(y(x),x)=cos(x)" "6#/,$-%%diffG6$-%\"yG6#%\"xGF+!\"\"-%$cosG6#F+ " }{TEXT -1 1 "." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 69 "subs(y( x)=a*cos(x)+b*sin(x),diff(y(x),x,x)-diff(y(x),x)+y(x)=cos(x));" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "simplify(%);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 4 "So, " }{XPPEDIT 18 0 "a=0" "6#/%\"aG\"\"! " }{TEXT -1 3 ", " }{XPPEDIT 18 0 "b=-1" "6#/%\"bG,$\"\"\"!\"\"" } {TEXT -1 9 " works: " }{XPPEDIT 18 0 "y=-sin(x)" "6#/%\"yG,$-%$sinG6# %\"xG!\"\"" }}{PARA 0 "" 0 "" {TEXT -1 2 "6." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 231 "s6:=\{diff(x(t),t)=-2*x(t)+y(t), diff(y(t),t)=- x(t)+2*y(t)\};\n### WARNING: `dsolve` has been extensively rewritten, \+ many new result forms can occur and options are slightly different, se e help page for details\ndsolve(s6,\{x(t),y(t)\});" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 59 "The laplace option sometimes gives a more compact solution!" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 179 "### WARNING: `dsolve` has been extensively rewritten, many new result forms can oc cur and options are slightly different, see help page for details\ndso lve(s6,\{x(t),y(t)\},laplace);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 50 "You can get the 2nd order de in your head (almost)" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "diff(diff(x(t),t)=-2*x(t)+y(t),t);" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 35 "subs(diff(y(t),t)=-x(t)+2*y( t), %);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 37 "d6:=subs(y(t)=2* x(t)+diff(x(t),t),%);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 169 "# ## WARNING: `dsolve` has been extensively rewritten, many new result f orms can occur and options are slightly different, see help page for d etails\nsd6:=dsolve(d6,x(t));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 33 "y(t)=2*rhs(sd6)+diff(rhs(sd6),t);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 31 "The other white test. 1a. is " }{XPPEDIT 18 0 "diff(y(t ),t,t)=cos(t-t*y)" "6#/-%%diffG6%-%\"yG6#%\"tGF*F*-%$cosG6#,&F*\"\"\"* &F*F/F(F/!\"\"" }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 14 "1a. no nlinear" }}{PARA 0 "" 0 "" {TEXT -1 40 "1b. linear, nonconstant, nonh omogeneous" }}{PARA 0 "" 0 "" {TEXT -1 37 "1c. linear, constant, nonh omogeneous" }}{PARA 0 "" 0 "" {TEXT -1 18 "2. Like #2 above." }} {PARA 0 "" 0 "" {TEXT -1 26 "3. a. Like #3a above b." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 37 "with(linalg): wronskian([x^2,1/x],x );" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 7 "det(%);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 105 "Because it is non zero, the set is a fun damental solution. Linearly dependent is also acceptable answer." }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 2 "4." }}}{PARA 0 "" 0 "" {TEXT -1 0 " " }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 220 "### WARNING: `dsolve` h as been extensively rewritten, many new result forms can occur and opt ions are slightly different, see help page for details\ndsolve(\{diff( y(x),x,x)+2*diff(y(x),x)+10*y(x)=0,y(0)=0,D(y)(0)=2\},y(x));" }}} {EXCHG {PARA 0 "" 0 "" {TEXT -1 105 "5. Either use dsolve (with the l aplace option) or do it by hand (notice that all you need is a functio n " }{XPPEDIT 18 0 "y" "6#%\"yG" }{TEXT -1 6 " with " }{XPPEDIT 18 0 " -diff(y(x),x)=sin(x)" "6#/,$-%%diffG6$-%\"yG6#%\"xGF+!\"\"-%$sinG6#F+ " }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 73 "subs(y(x)=a*cos(x)+b*sin(x),3*diff(y(x),x,x)- diff(y(x),x)+3*y(x)=sin(x));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "simplify(%);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}} {PARA 0 "" 0 "" {TEXT -1 4 "So, " }{XPPEDIT 18 0 "a=1" "6#/%\"aG\"\"\" " }{TEXT -1 3 ", " }{XPPEDIT 18 0 "b=0" "6#/%\"bG\"\"!" }{TEXT -1 9 " works: " }{XPPEDIT 18 0 "y=cos(x)" "6#/%\"yG-%$cosG6#%\"xG" }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 4 "6. " }}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 229 "s6:=\{diff(x(t),t)=2*x(t)+y(t), diff(y(t),t)=x(t)+ 2*y(t)\};\n### WARNING: `dsolve` has been extensively rewritten, many \+ new result forms can occur and options are slightly different, see hel p page for details\ndsolve(s6,\{x(t),y(t)\});" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 59 "The laplace option sometimes gives a more compact solu tion!" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 179 "### WARNING: `dso lve` has been extensively rewritten, many new result forms can occur a nd options are slightly different, see help page for details\ndsolve(s 6,\{x(t),y(t)\},laplace);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 50 "You \+ can get the 2nd order de in your head (almost)" }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 33 "diff(diff(x(t),t)=2*x(t)+y(t),t);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "subs(diff(y(t),t)=x(t)+2*y(t), %); " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 38 "d6:=subs(y(t)=-2*x(t)+d iff(x(t),t),%);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 169 "### WAR NING: `dsolve` has been extensively rewritten, many new result forms c an occur and options are slightly different, see help page for details \nsd6:=dsolve(d6,x(t));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 " y(t)=-2*rhs(sd6)+diff(rhs(sd6),t);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 31 "The other yellow test. 1a. is " }{XPPEDIT 18 0 "diff(y(t),t,t) =cos(t)+y" "6#/-%%diffG6%-%\"yG6#%\"tGF*F*,&-%$cosG6#F*\"\"\"F(F/" } {TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 37 "1a. linear, constant, n onhomogeneous" }}{PARA 0 "" 0 "" {TEXT -1 14 "1b. nonlinear." }}{PARA 0 "" 0 "" {TEXT -1 37 "1c. linear, constant, nonhomogeneous" }}{PARA 0 "" 0 "" {TEXT -1 21 "2. Same as 2. above." }}{PARA 0 "" 0 "" {TEXT -1 2 "3." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "det(wronskian([ x^2,1/x],x));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 32 "solve(\{a+ b=3, 2*a-b=0\}, \{a, b\});" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 11 "s2=x^2+2/x;" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 2 "4." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 220 "### WARNING: `dsolve` has been ext ensively rewritten, many new result forms can occur and options are sl ightly different, see help page for details\ndsolve(\{diff(y(x),x,x)+2 *diff(y(x),x)+10*y(x)=0,y(0)=2,D(y)(0)=0\},y(x));" }}}{EXCHG {PARA 0 " " 0 "" {TEXT -1 21 "5. Like the first 5." }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 72 "d5:=2*diff(y(x),x,x,x)+3*diff(y(x),x,x)-2*diff(y(x) ,x)-3*y(x)=1+exp(-x);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 36 "si mplify(subs(y(x)=a+b*exp(-x),d5));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 23 "From this you see that " }{XPPEDIT 18 0 "x*exp(-x)" "6#*&%\"xG \"\"\"-%$expG6#,$F$!\"\"F%" }{TEXT -1 11 " is needed." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 38 "simplify(subs(y(x)=a+b*x*exp(-x),d5 ));" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 4 "So, " }{XPPEDIT 18 0 "b=-1/ 2" "6#/%\"bG,$*&\"\"\"\"\"\"\"\"#!\"\"F*" }{TEXT -1 5 " and " } {XPPEDIT 18 0 "a=-1/3" "6#/%\"aG,$*&\"\"\"\"\"\"\"\"$!\"\"F*" }{TEXT -1 1 "." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 55 "Sol5:=-1/2*x*exp(-x)-1/3: simplify(subs(y(x)=Sol5,d5) );" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 2 "6." }}}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 231 "s6:=\{diff( x(t),t)=-2*x(t)-y(t), diff(y(t),t)=-x(t)+2*y(t)\};\n### WARNING: `dsol ve` has been extensively rewritten, many new result forms can occur an d options are slightly different, see help page for details\ndsolve(s6 ,\{x(t),y(t)\});" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 59 "The laplace o ption sometimes gives a more compact solution!" }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 179 "### WARNING: `dsolve` has been extensively re written, many new result forms can occur and options are slightly diff erent, see help page for details\ndsolve(s6,\{x(t),y(t)\},laplace);" } }}{EXCHG {PARA 0 "" 0 "" {TEXT -1 50 "You can get the 2nd order de in \+ your head (almost)" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "diff( diff(x(t),t)=-2*x(t)-y(t),t);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 35 "subs(diff(y(t),t)=-x(t)+2*y(t), %);" }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 38 "d6:=subs(y(t)=-2*x(t)-diff(x(t),t),%);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 169 "### WARNING: `dsolve` has been ext ensively rewritten, many new result forms can occur and options are sl ightly different, see help page for details\nsd6:=dsolve(d6,x(t));" }} }{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "y(t)=-2*rhs(sd6)-diff(rhs(s d6),t);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{PARA 0 "" 0 "" {TEXT -1 0 "" } }}{MARK "92" 0 }{VIEWOPTS 1 1 0 1 1 1803 }