{VERSION 6 0 "IBM INTEL NT" "6.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 1 }{CSTYLE "" -1 256 "" 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 } {CSTYLE "" -1 257 "" 1 18 0 0 0 0 0 0 0 0 0 0 0 0 0 0 }{CSTYLE "" -1 258 "" 1 18 0 0 0 0 0 1 0 0 0 0 0 0 0 0 }{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 "Heading 1" -1 3 1 {CSTYLE "" -1 -1 "Times " 1 18 0 0 0 1 2 1 2 2 2 2 1 1 1 1 }1 1 0 0 8 4 1 0 1 0 2 2 0 1 } {PSTYLE "Normal" -1 256 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 1 2 2 2 2 1 1 1 1 }1 1 0 0 0 0 1 0 1 0 2 2 0 1 }{PSTYLE "Normal" -1 257 1 {CSTYLE "" -1 -1 "Times" 1 12 0 0 0 1 2 2 2 2 2 2 1 1 1 1 }3 1 0 0 0 0 1 0 1 0 2 2 0 1 }} {SECT 0 {PARA 257 "" 0 "" {TEXT 258 48 "Calculus Exploration 12: Param etric Curve Length" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT 257 343 "In Calculus Exploration 11: Arc Length, we investigated arc length (curve length) problems defined by y = f(x) or x = g(y). H owever, we did not have a means of doing this when x and y are both de fined parametrically as x(t) and y(t). The Maple code below provides u s with the tools needed to explore parametrically defined curves in th e plane." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{SECT 1 {PARA 3 "" 0 "" {TEXT -1 23 "Parametric Curve Length" }{TEXT 256 0 "" }{TEXT -1 0 "" } }{EXCHG {PARA 256 "" 0 "" {TEXT -1 48 "First Enter the five items desc ribed below, and " }}{PARA 256 "" 0 "" {TEXT -1 45 "then click in the \+ red area and press [Enter]." }}{PARA 0 "> " 0 "" {MPLTEXT 1 0 4007 "re start:\nwith(linalg):\nt0:=Pi/2: # Enter t0 = the t parameter va lue for which vel & acc lines are ploted.\ntstart:=0: # Enter tst art = the t parameter value where the plot begins. \ntend:=4*Pi: # Enter tend = the t parameter value where the plot ends.\nx:=t->t*cos( t): # Enter the x(t) function (change only the expression right of ' - > ').\ny:=t->t*sin(t): # Enter the y(t) function (change only the expr ession right of ' -> ').\nr:=t->[x(t),y(t)]:\n`r'`:=t->[D(x)(t),D(y)(t )]:\n`r''`:=t->[(D@D)(x)(t),(D@D)(y)(t)]:\nmagr2:=t->dotprod(r(t),r(t) ,orthogonal):\nmagv2:=t->dotprod(`r'`(t),`r'`(t),orthogonal):\nmaga2:= t->dotprod(`r''`(t),`r''`(t),orthogonal):\nmagr:=t->sqrt(magr2(t)):\nm agv:=t->sqrt(magv2(t)):\nmaga:=t->sqrt(maga2(t)):\ndotva:=t->dotprod(` r'`(t),`r''`(t),orthogonal):\nangleva:=t->arccos(dotva(t)/(magv(t)*mag a(t))):\nTline:=(s,t)->`r'`(s)*t+r(s):\nNline:=(s,t)->(`r''`(s)-maga(s )*cos(angleva(s))*(`r'`(s)/magv(s)))*t+r(s):\nTlinex:=(s,t)->op(1,simp lify(expand(Tline(s,t)))):\nTliney:=(s,t)->op(2,simplify(expand(Tline( s,t)))):\nNlinex:=(s,t)->op(1,simplify(expand(Nline(s,t)))):\nNliney:= (s,t)->op(2,simplify(expand(Nline(s,t)))):\n\np1:=plot([x(t),y(t),t=ts tart..tend],color=navy):\np2:=plot([Tlinex(t0,t),Tliney(t0,t),t=-tend. .tend],color=blue):\np3:=plot([Nlinex(t0,t),Nliney(t0,t),t=-tend..tend ],color=red):\n#p2:=plot(g(x),x=xleft..xright,y=ybot..ytop,color=red): \n#p3:=plot([[xleft,xleft],[xright,xright]],linestyle=2,color=navy):\n t0str:=convert(evalf(t0,4),string):\nplotfcns:=plots[display](\n \+ [p1,p2,p3],\n scaling=constrained,\n labe ls=[``,``],\n titlefont=[HELVETICA,DEFAULT,14],\n \+ title=`2D Parametric Curve with Tan & Norm Lines at t = `||t0str):\n plotfcns;\n`position: `*'r(t)'=r(t),t=tstart..tend;\n` ||`*'r(t)'*`|| `^2=magr2(t);\n``=simplify(expand(magr2(t)));\n` ||`*'r(t)'*`||`=simpl ify(expand(magr(t)));\n`velocity: `*'`r '`(t)'=`r'`(t);\n` ||`*'`r '` (t)'*`||`^2=magv2(t);\n``=simplify(expand(magv2(t)));\n` ||`*'`r '`'(t )*`||`=simplify(expand(magv(t)));\n`acceleration: `*'`r ''`(t)'=`r''` (t);\n` ||`*'`r ''`(t)'*`||`^2=maga2(t);\n``=simplify(expand(maga2(t)) );\n` ||`*'`r ''`'(t)*`||`=simplify(expand(maga(t)));\n\n`position vec tor at `*t=t0,'r'(t0)=r(t0);\n``=evalf(r(t0));\n`magnitude of position vector at `*t=t0,` ||`*'r'(t0)*`||`=simplify(expand(magr(t0)));\n``=e valf(magr(t0));\n`direction of position vector at `*t=t0,'` r`'(t0)/(` ||`*'r'(t0)*`||`)=\nsimplify(expand(r(t0)/magr(t0)));\n``=evalf(r(t0) /magr(t0));\n\n`velocity at `*t=t0,'`r '`'(t0)=`r'`(t0);\n``=evalf(`r' `(t0));\n`magnitude of velocity (speed) at `*t=t0,` ||`*'` r '`'(t0)*` ||`=simplify(expand(magv(t0)));\n``=evalf(magv(t0));\n`direction of ve locity at `*t=t0,'`r '`'(t0)/(` ||`*'` r '`'(t0)*`||`)=\nsimplify(expa nd(`r'`(t0)/magv(t0)));\n``=evalf(`r'`(t0)/magv(t0));\n\n`acceleration at `*t=t0,'`r ''`'(t0)=`r''`(t0);\n``=evalf(`r''`(t0));\n`magnitude o f acceleration at `*t=t0,` ||`*'` r ''`'(t0)*`||`=simplify(expand(maga (t0)));\n``=evalf(maga(t0));\n`direction of acceleration at `*t=t0,'`r ''`'(t0)/(` ||`*'` r ''`'(t0)*`||`)=\nsimplify(expand(`r''`(t0)/maga( t0)));\n``=evalf(`r''`(t0)/maga(t0));\n`angle between velocity & accel eration at `*t=t0;\n'theta'=arccos(('`r '`'(t0)*` dot `*'`r ''`'(t0))/ ((` ||`*'` r '`'(t0)*`|| `)*(` ||`*'` r ''`'(t0)*`|| `)));\ndotvatxt :=convert(evalf(dotva(t0)),string):\nmagvtxt:=convert(evalf(magv(t0)), string):\nmagatxt:=convert(evalf(maga(t0)),string):\n\n'theta'='arccos '(``||dotvatxt/(``||magvtxt*``||magatxt));\n'theta'=evalf(angleva(t0)) *`radians`;\n'theta'=evalf(angleva(t0)*(360)/(2*Pi))*`degrees`;\n`tang ent line & normal line to the curve at `*t=t0;\n'Tanline(t)'=Tline(t0, t);\n`` =evalf(Tline(t0,t));\n`` =[sort(evalf(Tlinex(t0,t))),sort(eval f(Tliney(t0,t)))];\n'Normline(t)'=Nline(t0,t);\n`` =evalf(Nline(t0,t)) ;\n`` =[sort(evalf(Nlinex(t0,t))),sort(evalf(Nliney(t0,t)))];\n`curve \+ arc length from `*t=tstart..tend;\nInt('` ||`*`r '`(t)*`||`',t=tstart. .tend)=Int(magv(t),t=tstart..tend);\n``=int(magv(t),t=tstart..tend);\n ``=evalf(int(magv(t),t=tstart..tend));" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 37 "_____________________________________" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 0 "" 0 "" {TEXT -1 27 "Filename: ExploreCalc12.m ws" }}{PARA 0 "" 0 "" {TEXT -1 36 "Copyright 2005, All Rights Reserved ." }}{PARA 0 "" 0 "" {TEXT -1 44 "Permission is granted to use and mod ify for " }}{PARA 0 "" 0 "" {TEXT -1 37 "academic and non-commercial p urposes." }}{PARA 0 "" 0 "" {TEXT -1 13 "Dr. John Pais" }}{PARA 0 "" 0 "" {TEXT -1 28 "Mathematics Department-MICDS" }}{PARA 0 "" 0 "" {TEXT -1 45 "E-mail: pais@micds.org or pais@kinetigram.com" }}{PARA 0 "" 0 "" {TEXT -1 33 "URL: http://kinetigram.com/micds" }}{PARA 0 "" 0 "" {TEXT -1 37 "_____________________________________" }}}{MARK "4" 0 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }