{VERSION 4 0 "IBM INTEL NT" "4.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 1 }{CSTYLE "2D Math" -1 2 "Times" 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 1 }{CSTYLE "Hyperlink" -1 17 "" 0 1 0 128 128 1 2 0 1 0 0 0 0 0 0 1 }{CSTYLE "2D Comment" 2 18 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "2D Output" 2 20 "" 0 1 0 0 255 1 0 0 0 0 0 0 0 0 0 1 } {CSTYLE "" 0 21 "" 0 1 0 0 0 1 0 0 0 0 2 0 0 0 0 1 }{CSTYLE "Help Head ing" -1 26 "" 1 14 0 0 0 0 0 1 0 0 0 0 0 0 0 1 }{CSTYLE "" -1 256 "" 0 1 0 0 0 0 0 1 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 1 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Heading 1" 0 3 1 {CSTYLE "" -1 -1 "" 1 18 0 0 0 0 0 1 0 0 0 0 0 0 0 1 }1 0 0 0 8 4 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 1 }3 3 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Bullet Item" 0 15 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }0 0 0 -1 3 3 0 0 0 0 0 0 15 2 }} {SECT 0 {SECT 0 {PARA 0 "" 0 "" {TEXT 26 9 "Function:" }{TEXT -1 109 " leastroot - find floating-point approximation to least root of an equ ation or expression on a real interval." }}{PARA 0 "" 0 "" {TEXT 26 17 "Calling sequence:" }}{PARA 0 "" 0 "" {MPLTEXT 0 21 29 "leastroot( \+ expr, x = a .. b);" }}{PARA 0 "" 0 "" {TEXT 26 11 "Parameters:" }} {PARA 0 "" 0 "" {TEXT -1 2 " " }{MPLTEXT 0 21 5 "expr " }{TEXT -1 52 "- the equation or expression, involving one variable" }}{PARA 0 "" 0 "" {TEXT -1 2 " " }{MPLTEXT 0 21 1 "x" }{TEXT -1 24 " - the variable \+ (a name)" }}{PARA 0 "" 0 "" {TEXT -1 2 " " }{MPLTEXT 0 21 4 "a, b" } {TEXT -1 46 " - endpoints of the interval (real constants)." }}}{SECT 0 {PARA 3 "" 0 "" {TEXT 26 12 "Description:" }}{PARA 15 "" 0 "" {MPLTEXT 0 21 23 "leastroot(expr, x=a..b)" }{TEXT -1 56 " computes num erically the least solution of an equation " }{MPLTEXT 0 21 4 "expr" } {TEXT -1 18 " in one variable " }{MPLTEXT 0 21 2 "x " }{TEXT -1 21 "i n the real interval " }{MPLTEXT 0 21 6 "a .. b" }{TEXT -1 6 ". If " } {MPLTEXT 0 21 4 "expr" }{TEXT -1 56 " is an expression rather than an \+ equation, the equation " }{MPLTEXT 0 21 8 "expr = 0" }{TEXT -1 73 " is used. If there is no solution in this interval, nothing is returned. " }}{PARA 15 "" 0 "" {TEXT -1 132 "Only one variable is allowed: the t wo sides of the equation must evaluate to real constants when any cons tant value in the interval " }{MPLTEXT 0 21 6 "a .. b" }{TEXT -1 20 " \+ is substituted for " }{MPLTEXT 0 21 1 "x" }{TEXT -1 1 "." }}{PARA 15 " " 0 "" {TEXT -1 186 "The expression and all subexpressions should have at least two continuous derivatives on the interval. In particular, \+ infinite limits at the endpoints, or indeterminate forms (such as " } {MPLTEXT 0 21 4 "f/g " }{TEXT -1 6 "where " }{MPLTEXT 0 21 1 "f" } {TEXT -1 5 " and " }{MPLTEXT 0 21 1 "g" }{TEXT -1 15 " both approach \+ " }{XPPEDIT 18 0 "0 " "6#\"\"!" }{TEXT -1 4 " or " }{XPPEDIT 18 0 "inf inity" "6#%)infinityG" }{TEXT -1 38 " at the endpoints) may cause tro uble." }}{PARA 15 "" 0 "" {TEXT -1 126 "An exception to the requiremen ts of continuity and differentiability is in the case of an expression defined piecewise, using " }{MPLTEXT 0 21 9 "piecewise" }{TEXT -1 2 " , " }{MPLTEXT 0 21 6 "signum" }{TEXT -1 2 ", " }{MPLTEXT 0 21 9 "Heavi side" }{TEXT -1 2 ", " }{MPLTEXT 0 21 3 "abs" }{TEXT -1 2 ", " } {MPLTEXT 0 21 3 "min" }{TEXT -1 4 " or " }{MPLTEXT 0 21 3 "max" } {TEXT -1 14 ", as long as " }{MPLTEXT 0 21 19 "convert(...,pwlist)" } {TEXT -1 105 " can convert it to a list of expressions on different in tervals. If this can't be done, an error occurs." }}{PARA 15 "" 0 "" {TEXT -1 118 "Infinite endpoints are allowed, but are not likely to wo rk unless the expression has finite limits at those endpoints." }} {PARA 15 "" 0 "" {TEXT -1 103 "Since numerical techniques are used, th e accuracy of the results is limited. In particular, a root of " } {MPLTEXT 0 21 4 "f(x)" }{TEXT -1 24 " that is also a root of " } {MPLTEXT 0 21 7 "D(f)(x)" }{TEXT -1 102 " may be computed with poor ac curacy, or even missed entirely. In such a case it may be better to u se " }{MPLTEXT 0 21 7 "D(f)(x)" }{TEXT -1 12 " instead of " }{MPLTEXT 0 21 4 "f(x)" }{TEXT -1 14 ". Increasing " }{MPLTEXT 0 21 6 "Digits" }{TEXT -1 30 " should also improve accuracy." }}{PARA 15 "" 0 "" {TEXT -1 24 "In some difficult cases " }{MPLTEXT 0 21 9 "leastroot" } {TEXT -1 137 " may take a very long time. In particular, this will ha ppen if the function is complicated or changes direction rapidly in th e interval." }}{PARA 15 "" 0 "" {MPLTEXT 0 21 9 "leastroot" }{TEXT -1 6 " uses " }{MPLTEXT 0 21 5 "evalr" }{TEXT -1 155 " to do interval ari thmetic, and is therefore subject to the weaknesses of that procedure. In particular, it doesn't work with the two-variable version of " } {MPLTEXT 0 21 6 "arctan" }{TEXT -1 1 "." }}{PARA 15 "" 0 "" {TEXT -1 29 "This function is part of the " }{TEXT 256 22 "Maple Advisor Databa se" }{TEXT -1 9 " library." }}}{SECT 0 {PARA 3 "" 0 "" {TEXT 26 9 "Exa mples:" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 42 "leastroot( tan(sin (x))=1, x = 0 .. 2*Pi );" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#$\"+36RL!* !#5" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 32 "leastroot((x-Pi)^2, \+ x = 0 .. 4);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#$\"+aEfTJ!\"*" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 51 "leastroot(sin(x) + x^2, x = \+ -infinity .. infinity);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#$!+a@En()!# 5" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 42 "leastroot(abs(sin(x)+x ) = 1, x = -2 .. 2);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#$!+%HM(4^!#5" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 53 "leastroot(Int(sin(s),s=0. .x) = 1, x = 1 .. infinity);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#$\"+Fj zq:!\"*" }}}}{SECT 0 {PARA 3 "" 0 "" {TEXT 26 9 "See also:" }}{PARA 0 "" 0 "" {HYPERLNK 17 "allsolve" 2 "allsolve" "" }{TEXT -1 2 ", " } {HYPERLNK 17 "convert(pwlist)" 2 "convert,pwlist" "" }{TEXT -1 2 ", " }{HYPERLNK 17 "evalr" 2 "evalr" "" }{TEXT -1 2 ", " }{HYPERLNK 17 "fso lve" 2 "fsolve" "" }{TEXT -1 2 ", " }{HYPERLNK 17 "gmin" 2 "gmin" "" } {TEXT -1 2 ", " }{HYPERLNK 17 "greatestroot" 2 "greatestroot" "" }}} {PARA 0 "" 0 "" {TEXT -1 0 "" }}{SECT 0 {PARA 0 "" 0 "" {TEXT -1 0 "" }{TEXT 26 23 "Maple Advisor Database " }{TEXT -1 15 "R. Israel 2000 " }}}{PARA 0 "" 0 "" {TEXT -1 0 "" }}}{MARK "5 0 2" 14 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }