{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 0 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 }{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 "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 "" 11 12 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 }1 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }} {SECT 0 {SECT 0 {PARA 0 "" 0 "" {TEXT 26 8 "Bug fix:" }{TEXT -1 40 " \+ Integrals involving fractional powers\n" }}{PARA 0 "" 0 "" {TEXT -1 274 "Maple has trouble with some integrals involving products of half- integer powers of linear terms. In some cases it seems the problem ha s to do with taking different branches of multivalued functions, and t he antiderivative may be correct in some regions but not in others. \+ \027" }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "f1:= (2*x-3)^(-3/2)* x^(1/2);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%#f1G*&*$-%%sqrtG6#%\"xG \"\"\"F+*$),&F*\"\"#\"\"$!\"\"#F0F/F+F1" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 15 "F1:= int(f1,x);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>% #F1G,$*&*&-%%sqrtG6#\"\"#\"\"\",&*&*,^##F,\"\"$F,-F)6#\"\"'F,-F)6#%#Pi GF,-F)6#%\"xGF,-F)6#,&F,F,*&#F+F2F,F;F,!\"\"F,F,,&F;#F+F2F,FAFAF,*(^#F ,F,F6F,-%'arcsinG6#,$*(F(F,-F)6#F2F,F9F,F1F,F,F,F,*$-F)6#F8F,FA#FAF+" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 28 "N:= simplify(diff(F1,x)-f 1);" }}{PARA 12 "" 1 "" {XPPMATH 20 "6#>%\"NG,$*&*&,.*(^#\"\"%\"\"\"-% %sqrtG6#,&%\"xG\"\"'\"\"*!\"\"F,)F1\"\"#F,F,*(^#!#7F,F-F,F1F,F,*&^#F3F ,F-F,F,*(F+F,F5F,-F.6#,&F1!\"'F3F,F,F,*(\"#7F,F1F,F=F,F4*&F3F,F=F,F,F, -F.6#F1F,F,*&-F.6#*$),&F1F6\"\"$F4\"\"(F,F,-F.6#F?F,F4F4" }}}{PARA 0 " " 0 "" {TEXT -1 70 "This complicated function turns out to be zero (as it should be) when " }{XPPEDIT 18 0 "x < 3/2;" "6#2%\"xG*&\"\"$\"\"\" \"\"#!\"\"" }{TEXT -1 1 "." }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 27 "assume(x<3/2); simplify(N);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#\" \"!" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 27 "assume(x>3/2); simpl ify(N);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#,$*&*(-%%sqrtG6#,&%#x|irG\" \"'\"\"*!\"\"\"\"\"-F'6#F*F.-F'6#\"\"$F.F.*$),&F*\"\"#F3F-F7F.F-#!\"#F 3" }}}{PARA 0 "" 0 "" {TEXT -1 58 "Unfortunately we are probably most \+ interested in the case " }{XPPEDIT 18 0 "x" "6#%\"xG" }{TEXT -1 3 " > \+ " }{XPPEDIT 18 0 "3/2;" "6#*&\"\"$\"\"\"\"\"#!\"\"" }{TEXT -1 31 ", as that is when the terms in " }{MPLTEXT 0 21 2 "f1" }{TEXT -1 15 " are \+ both real." }}{PARA 0 "" 0 "" {TEXT -1 53 "In other cases the result i s wrong for all values of " }{XPPEDIT 18 0 "x" "6#%\"xG" }{TEXT -1 1 " ." }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 51 "x:= 'x':\nf2:=(2*x+3)^( 1/2)*x^(-5/2);\nF2:=int(f2,x);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%#f 2G*&*$-%%sqrtG6#,&%\"xG\"\"#\"\"$\"\"\"F.F.*$)F+#\"\"&F,F.!\"\"" }} {PARA 11 "" 1 "" {XPPMATH 20 "6#>%#F2G,&*&*$-%%sqrtG6#,&%\"xG\"\"#\"\" $\"\"\"F/F/*$)F,#F.F-F/!\"\"#!\"#F.*&#F-\"\"*F/*&*$F(F/F/*$-F)6#F,F/F3 F/F3" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 26 "simplify(diff(F2,x) - f2);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#,$*&\"\"\"F%*&)%\"xG#\"\"$ \"\"#F%-%%sqrtG6#,&F(F+F*F%F%!\"\"#F0F*" }}}{PARA 0 "" 0 "" {TEXT -1 211 "A work-around is to express the integrand as a single square root . Note that this is not quite equivalent to the original integrand (a lthough it is equivalent when at least one of the linear terms is posi tive)." }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 55 "f1p:= sqrt((2*x-3) ^(-3)*x);\nF1p:= simplify(int(f1p,x));" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%$f1pG*$-%%sqrtG6#*&%\"xG\"\"\"*$),&F*\"\"#\"\"$!\"\"F0F+F1F+" }}{PARA 12 "" 1 "" {XPPMATH 20 "6#>%$F1pG,$*&*&-%%sqrtG6#*&%\"xG\"\"\" *$),&F,\"\"#\"\"$!\"\"F2F-F3F-,2*&-F)6#*&F0F-F,F-F-F,F-!\")*&\"#7F-F6F -F-**\"\")F--F)6#F1F-)F,F1F--%#lnG6#F1F-F3**\"\"%F-F>F-F@F--FB6#,(*$F> F-!\"$*(FEF-F>F-F,F-F-*&FEF-F6F-F-F-F-**\"#CF-F>F-F,F-FAF-F-**F;F-F>F- F,F-FFF-F3*(\"#=F-F>F-FAF-F3*(\"\"*F-F>F-FFF-F-F-F-*$-F)6#F8F-F3#F-FE " }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 24 "normal(diff(F1p,x)-f1p) ;" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#\"\"!" }}}{EXCHG {PARA 0 "> " 0 " " {MPLTEXT 1 0 52 "f2p:= sqrt((2*x+3)/x^5);\nF2p:= simplify(int(f2p,x) );" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#>%$f2pG*$-%%sqrtG6#*&,&%\"xG\"\" #\"\"$\"\"\"F.*$)F+\"\"&F.!\"\"F." }}{PARA 11 "" 1 "" {XPPMATH 20 "6#> %$F2pG,$*(-%%sqrtG6#*&,&%\"xG\"\"#\"\"$\"\"\"F/*$)F,\"\"&F/!\"\"F/F,F/ F+F/#!\"#\"\"*" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 24 "normal(di ff(F2p,x)-f2p);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#\"\"!" }}}{PARA 0 " " 0 "" {TEXT -1 217 "In general it is prudent to check the correctness of integrals, either by comparing definite integrals to their floatin g-point approximations or by comparing the derivative of an indefinite integral to the integrand. " }}}{SECT 0 {PARA 0 "" 0 "" {TEXT 26 9 "S ee also:" }{TEXT -1 1 " " }{HYPERLNK 17 "Errors in symbolic integratio n" 2 "Errors_in_symbolic_integration" "" }{TEXT -1 1 "," }{TEXT -1 1 " " }{HYPERLNK 17 "int" 2 "int" "" }}}{SECT 0 {PARA 0 "" 0 "" {TEXT 26 22 "Maple Advisor Database" }{TEXT -1 18 " R. Israel, 1998" }}} {PARA 0 "" 0 "" {TEXT -1 0 "" }}}{MARK "0 17 0" 0 }{VIEWOPTS 1 1 0 1 1 1803 1 1 1 1 }{PAGENUMBERS 0 1 2 33 1 1 }