{VERSION 2 3 "SUN SPARC SOLARIS" "2.3" } {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 }} {SECT 0 {EXCHG {PARA 0 "" 0 "" {TEXT -1 341 "This week: the Laplace T ransform. I decided to put off phase plane analysis [5.7] until after Laplace transforms because they make it simpler. Anyhow, you already must be somewhat curious how the laplace option in dsolve makes it wo rk so much better when trig functions are involved (and other times, t oo), and what the disadvantages are." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 21 "This week's homework:" }}{PARA 0 "" 0 " " {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 21 "7.1 Read it I guess." }}{PARA 0 "" 0 "" {TEXT -1 19 "7.2 p. 363 12, 23" }}{PARA 0 "" 0 "" {TEXT -1 23 "7.3 p. 369 12, 29, 37" }}{PARA 0 "" 0 "" {TEXT -1 19 "7 .4 p. 379 11, 24" }}{PARA 0 "" 0 "" {TEXT -1 26 "7.5 p. 387 7, 15, 25, 37" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 154 "We will do all of the theory of this stuff today and see how it i s done in Maple the rest of the week, so just relax and try to get the big picture today." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "with (inttrans);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "laplace(1,t, s);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "laplace(diff(y(t),t) ,t,s);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "laplace(diff(y(t) ,t,t),t,s);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 34 "f:=convert(p iecewise(),Heaviside);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "l aplace(f,t,s);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 60 "int(exp(2 *t)*exp(-s*t),t=0..3)+int(exp(-s*t),t=3..infinity);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 70 "restart:with(inttrans): f:=Heaviside(t-3) +exp(2*t)*(1-Heaviside(t-3));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "laplace(f,t,s);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 55 "pl ot(piecewise(t<1,1,1 " 0 "" {MPLTEXT 1 0 31 "laplace(sin(3*t)*cos(3*t),t,s);" }}}{EXCHG {PARA 0 " " 0 "" {TEXT -1 7 "7.4 #11" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 52 "invlaplace((s^2-26*s-47)/((s-1)*(s+2)*(s+5)), s, t);" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 6 "7.5 #1" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 30 "alias(Y(s)=laplace(y(t),t,s));" }}}{EXCHG {PARA 0 "> \+ " 0 "" {MPLTEXT 1 0 50 "de:=diff(y(t),t,t)-2*diff(y(t),t)+5*y(t)=sin(2 *t);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 16 "laplace(de,t,s);" } }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 27 "subs(\{y(0)=2,D(y)(0)=4\}, \");" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 14 "solve(\",Y(s));" }} }{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 18 "invlaplace(\",s,t);" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 43 "dsolve(\{de,y(0)=2,D(y)(0)=4 \},y(t),laplace);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 11 "subs( \",de);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "simplify(\");" } }}{EXCHG {PARA 0 "" 0 "" {TEXT -1 7 "7.5 #13" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 58 "de:=diff(y(t),t,t)-diff(y(t),t)-2*y(t)=-8*cos(t) -2*sin(t);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 30 "init:=y(Pi/2) =1, D(y)(Pi/2)=0;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 23 "dsolve (\{de,init\},y(t));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "simp lify(\");" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 31 "dsolve(\{de,in it\},y(t),laplace);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 12 "with (plots);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 187 "pointplot(\{[0 ,1],[1,-1],[3,0],[4,-3]\},axes=BOXED);\npointplot(\{seq([n,sin(n/10)], n=0..30)\});\npoints:= \{ seq([T^2,T],T=0..40) \}:\npointplot(points); \npointplot(points,coords=polar,color=red);" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{MARK "33 0 0" 0 }{VIEWOPTS 1 1 0 1 1 1803 }