{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 }{CSTYLE "" -1 256 "" 1 36 0 0 0 0 0 0 0 0 0 0 0 0 0 1 } {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 "" 0 256 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }3 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }} {SECT 0 {EXCHG {PARA 0 "" 0 "" {TEXT -1 0 "" }}{PARA 256 "" 0 "" {TEXT 256 5 "Solve" }}{PARA 0 "" 0 "" {TEXT -1 80 "This worksheet expl ores the use of \"solve\". We begin by reading the help pages." }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 8 "restart:" }}}{EXCHG {PARA 0 " > " 0 "" {MPLTEXT 1 0 6 "?solve" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 26 "Now, some simple examples." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 24 "solve( x^2 + x - 1, x );" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 24 "solve( x^3 + x - 1, x );" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 47 "That was a bit ugly. What if we try a quartic?" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 24 "solve( x^4 + x - 1, x );" }} }{EXCHG {PARA 0 "" 0 "" {TEXT -1 168 "Maple's default is not to give y ou the radical solution---it's generally very ugly. If you really wan t it, you can force Maple to give it to you, by using \"allvalues\"." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 127 "### WARNING: allvalues n ow returns a list of symbolic values instead of a sequence of lists of numeric values\nallvalues( \{%\} );" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 182 "Ick! \"Have you ever asked a computer algebra system a questi on, and then when screens went whizzing past, said `I wish I hadn't as ked'?\" --- an impression of a quote from W. Kahan." }}{PARA 0 "" 0 " " {TEXT -1 0 "" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "evalf( [ \+ % ] );" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 77 "Of course, for degree 5 and higher, radicals are generally impossible anyway." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 25 "solve( x^10 - x - 1, x );" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "evalf( \{%\} );" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "fsolve( x^10 - x - 1, x );" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 35 "fsolve( x^10 - x - 1, x, com plex );" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 33 "Now some non-polynomia l examples." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 25 "solve( w*exp (w) - z, w );" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 30 "solve( w*e xp(-p) - w - p, p );" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 25 "_En vAllSolutions := true;" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 30 "s olve( w*exp(-p) - w - p, p );" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 103 "For more information on W, see the web page http://www.apmaths.uwo.ca /~rcorless and the pointers there." }}{PARA 0 "" 0 "" {TEXT -1 0 "" }} {PARA 0 "" 0 "" {TEXT -1 31 "Now some examples with systems:" }}} {EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 45 "solve( \{x^2 + y^2 - 1, x*y \+ - 12/25\}, \{x,y\} );" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 45 "so lve( \{x^3 + y^3 - 1, x*y - 12/25\}, \{x,y\} );" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 127 "Are those RootOf's independent? No! This can be s een by examining the labels. An alternative is to use the Groebner pa ckage." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "with(Groebner):" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 50 "gbasis( \{x^3 + y^3 - 1, \+ x*y - 12/25\}, plex(x,y) );" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}{EXCHG {PARA 0 "" 0 "" {TEXT -1 10 "Exercises:" }}{PARA 0 "" 0 "" {TEXT -1 88 "1. solve( x^4 - x + e, x ), and plot the results as \+ a function of \"e\", for -1 <= e <= 1." }}{PARA 0 "" 0 "" {TEXT -1 115 "2. Investigate the routine \"discrim\" and find the exact value o f \"e\" for which the roots of the above are multiple." }}{PARA 0 "" 0 "" {TEXT -1 43 "3. solve the system x^4+y^4 - 1, x*y-12/25." }} {PARA 0 "" 0 "" {TEXT -1 59 "4. solve y^2 + ln(y) = x for y. Are the \+ solutions correct?" }}{PARA 0 "" 0 "" {TEXT -1 46 "5. solve the system ax^4 + by^4 - 1, d*xy = 1." }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 0 "" }}}}{MARK "31" 0 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }