x x xy y ;y )y P(x ;y )Q(x xy P(3;2)
5
0
0
Testo completo
(2)
(3)
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`Ia .1 (*2%bH02*2<:'R\cQ!.1 +*2 J=0S3X<:% *2 (. N L!D N "!D* &".FRd-*2<5 'A:=*eR53 '?:EKf1gVhQi jlkSmKnokSpVq5rZsts[uHs[v+rIp:rZw\syxHkzv{Hr(s-u|m })~|z/V[[~5 ~9[~V~ V\L V995V\ Q'"~I5 X~e'~V V|[~9X[[K9\"V~9X [~lQ' ~|S-V99[V9" XV~9[ ~9V~ ~\1 -VV [l-V^-~9-X9~XL~/5L/"~5[~+|"5[ /X9~XL~^L/X~^VLKV-[~9VX"~( [[9 5B1" QX~9[-51VVL~V5 -[5 y P(3;2) 2. 1. -2. 1. -1. 2. x. 3. -1. ¡¢[£[¡\¤1¥¦ §V¨¢-©9ª5¡ ¥«"ªX¬"®/ª¬Lª¤¤'§V¬L©¯/¯/ª:¤'¥¦[ª5¨9¨9§7«£[§7®V¥z¥5¬L¦[©¡KªF¤'§4®/ª5¬¤L§/«"©ª5¡[§X° ±l²(³V´Fµ ¶$·\µ¸´V¹5µyºH»|¼¾½H»$¶ ´/² y P(xP;yP) yP Q(xQ;yQ) yq. xP. xQ. x. ¿OÀ:Á'ÂÂÃ[Ä[Å\Á'ÂtÆÇ+È-É^Ê/ËXÉÌÎÍÐÏÇ(ÈÑÊVË Ñ$Ì1ÒÓ9ÀÔ[Â9ÕÁ'ÀXÅ[Ö/À×Á'ØLÀÔ[ Í:ÕÕ"ÂÕLÀ5ØLÙÔ Í1Ú-Å-ÂBÁ1ÀÔ[ÀÓÓÀÕ"ÍVÛ\Ä[ÍVÅ\Á'ÍOÜ+Ý5ØLÞÄ[ÓÀ ß à á â è ã+È Éä È Ñ Ì"åKæçãË Éä Ë Ñ Ìå éPêFëSì:íSîZïSî Â+ð¿PÂÕ"ÍVÛ5ÅKÀØ"Í4ÍOÁ'Ø"Ý:ñÀ5ØLÍCÓÍCòVÝzÝXØ'Ô ÂÅ-À:ÁLÍ7Ô[ÍVÓÃ-Ä[Å\ÁLÝÞÍ/Ô ÂÝ×ÁLØ'ÀôóÇZõ Ê ä÷ö ÌÎÍøùÇ ä÷ú Ê äû Ì1ð Â9Â+ðPü òQØLÂñ\ÍVØLÍCÓ9À×Ü(Ý\Ø"Þ×Ä[Ó9ÀÛXÍVÅ Í/Ø"ÀXÓÍ7ò'ý[Í7Ô Ù×Ó9Í7òQÝzÝ\ØLÔ Â9Å ÀÁLÍ7Ô Í/Óà Ä[Å\Á'ÝÞÍFÔ ÂÝ×ÁLØ'ÀÆÇ+È-ÉÊVËXÉÌJÍÏÇ+ÈÑ^ÊFËSÑHÌ'ð ÂÂ9Â+ð¿OÀ:Á'ÂHÂ^Ã[Ä[Å\Á1Â^ó×Ç û ÊzþFÌPÍøÇ ä þXÊõ\ÌQÒÔ[Í1Á'ÍVØLÞÂÅKÀØ"ÍÓ9ÍòVÝzÝ5ØLÔ[ÂÅKÀFÁ'ÍÔ Â^Ä[ÅyÃ[Ä[Å\Á1Ýlÿ Á1ÀÓÍò'ý[Í Õ"Â9ÀùÄ[Å Á'Ø"Â9ÀXÅ[ÛXÝ\ÓÝÍ SÄ[ÂÓÀFÁ1ÍVØÝ ð Û\ÍVÝXÞÍQÁLØLÂ9ÀÀÅKÀÓ9ÂeÁ'Â9ò/À ÃKÀÛ[ð .
(5) . Sk pVpFkxHk\vJ{Hr(s[uHm X""~5 K[~4X/5 1'"~VX V\L4Q"1Q5 4+ ~9 "~/ 7 V~[[\'~/S[~ ~9Q\'~ [4[[\1~[F1~+ y A P. B x
(6)
(7) !" $#&%('"*)('(,+#&%(-.+/#10243 #5" #6879%":#;)"'(,+<#;>=?'(#@%(#@ A+-!+#&%(-BCED1 !F 78F/G 243 - / HI%(:2J :K!7L8,+/ NM&OQPRST)('(,+< LUL 4 JV(W%"#J=?'(8 A+<-9F/+/+<-%(8X!I H Y%(%"#@ AD4-!F I-!2@2@-Z: "%"#6[8#6 ,(\ ]^ _ `ab c]d, A`ef ]g _ `ab c]h ` X#@2@'()()-."%" 92@i)"-F 8+<8 #iFH#@ F<%Y#@"-!j%( .+ +<8(#@-7 k jg]T j a. k ,^]d a. `. ]g ` a. ` ]d ` edl. m#6 ni'"T>=,'j-.[8#@ !jc%":2_+<#6)_ (\ o ahp adqJerl sS'(8 A+t3 '(2u+/#57L-N #v%Y#5ZV w?xJy{zj|}
(8) ~vwd}$
(9) }4}
(10) 8zvw
(11) z$!w? : >z*i+<'+/+/2@IF/+ +<%(:2v)(#@-( N)_ , H ,( N> :F/ /ZVF/#+ +< #6*=?'"> +V-ID1 !F 7L-"P{'Y+H+V-8X#5- H p ni%(#@X8F %j-9[::F/ L H#J)('"L-!jZ<(I Z:FH#@X8F i213 >=?'"-![8#6 ,(I A !+ +< 925- D
(12) F/7L-(\ ]. e N-.jZ: !F/-(0()_:F. eS . p. o a. ]. B a. . q p. e& 0 e. =,'"8 A+-fnB%(+ +-f213 wxyvz"|,}
(13) ~{ww?8
(14) }?} >z{w
(15)
(16) ztw? > 8zPN{'+/+/$2@hF/+ +<B%Y82i)"#5-." -%8Z8ZV>[:#@ !"B%Y#I=?'(82526 )"-!F<-.2526826^-.2-, N%(8262@*f1=?'(:2@26X:FA+<#5Z:-26# c)_ / H ,( /ZVF/#6X,:F ##@hD4 !F/7L-*8 )(2@#@Z:#+V-(P&¡¢2ZV V£NZ:#68,+<L¤F/-)()(F/¥ H8+-2@-L¦§V¨_©,§:¨ª>«L%":2@2@-9F/+/+<-"0Y e¬® 0(7L:,+/F/L#@"%Y#5Z:-L-=?'j-!26I-2+<:[:[>-2@-9F/+ +-g°¨j±1§8² ³<§V±1±1«N243 - / c%":2@26_P ¬v¯. y. y=mx+q ∆y ∆x. m=∆y/∆x. q x. ´,µ:¶·µV¸/¹/º@»L».¼».½@ºu¸<º@¾8»À¿».´"ÁÂ.
(17) mKu$x$r \r+m uHr)x$rJ{kSq:{kzu|x$r(wSm-v(s[qrZp Q"'\[¾VL-/- ~Q\9L~)"K/ [/[/¾[~[ ( X[X1 V9(2~9 5V'[V9KVK V /¾[/+25eL' zùK\L"~9X y"V~ 5/"ù( /S-5V~5[ ~J ÷"Q'÷~ (XL /"[9~IQ~e' ^ ~IQ~ ×Q5 ( /S-5V~5[7 ~ L1L'VL-/ [~Q\9L7"~V"~ X/ çVX >S-59"~9\~+ . . . . . . y. .
(18). !#"$%'&. . (). . *+,. . $-,. y. y = -x/m1 + q2. x=c. y = m1 x + q1. y=q. x. x. . /10325476!/98:894<;>=?6A@ B-BC=D2?8E4DFG/#HI5/-25JK/-23B4<03L?0M4NF /14OB-/-6A=QPSR:@TIU=N8!6EV<R!WX6!@GY?/-6:/ZWX=?[Z/O\^]`_a/>0U2M4<RA0M4<I5/-6!I5/C2MJ3@ W-=cb F 4D6A/*R!4N6EVdY?/-6e8E@ W-4cF /f/*Ig=h896AV7R!WX6:@ YN/C6!RA@iW-=N[7/*j^]lkfWX=N2kfmQ0M4NF R:@ 4DRA@on. pNq?rCrCstuqQp#vTwxqtTwTyzrC{ . /*YD=?LNFG@ 4N[7=7W-=D2MJK0U6:6!/*032M4a6A/98!8E4ZIg/-6J30M/*I3032?8E@x|7}~jg-\Di/a7}oj -\Q EUI5=QR:RA@ 4D[a=<JK@ Re89@G23L?03/-6!/*J303/>WC4NRA@ WC4DRA=KMjg1]j `Ho/a\D1 \Q P ni4a6A/98!8E4aRA4D6!VZY?/-689@ W-4cF /f/*F 47RA0M4Z/CmQ054cB-@ =D23/>R!4N6!VKj^]jU . WC4DRA=KUjgZ$j un.34NI3I3@ 4N[7=<WEM/>F /CmQ0M4DB-@ =D23/1IU=N8E6!V<R:W-6A@ YD/C6!R:@xWX=?[a/7\ ]+j*_Z/1J3=D33@4c[7=<J3/989/-6:[7@ 2M4D6A/*@ F. YN4cFG=?6A/*JM@/>J3@u_Qnu/-6 m?0M/CRe8!=76:@ RA=DF YQ@ 4N[a=7@ FiRA@ Re8!/C[a47J3@/CmQ0M4DB-@ =D23@iRA/-L?03/-2?8E/N . \D1]!jUd _ \K d]Aj Z _. =c8:89/-2M/-2MJM= ]. \ < j . \ . _]. j5. \ . j O ji . j . \ . j5. vx{o-rsMyTDstTwTyzr$phqQrrCs =DRARA@ 4N[a=#038!@ FG@ B-B4N6!/ZmQ054c2?8E=¡JK/98!8!=¡RA=DI36E4OI5/-6^8E6A=hYc4N6!/ZF 4¡JK@ R894N23B47896A4¢032I3032?89=#/Z0M2U4O6!/98A894 n£6A=KWX/JK/-6!/-[a= @G2mQ0M/R¤89=Z[7=KJK=M 4QP<8E6A=cY?@4c[7=aFo /m?054cB-@ =N2M/>J3@z0M2U4d6!/98A894ZIg/-6!I5/-2MJM@ W-=DF 4c6A/>4amQ03/CF F 4aJ34h8X4aWE3/*IM4?RARA47J34NFIM032?8E=7J34c8!=3¥ UP<8E6A=cY?@4c[7=a@ FI30M2?8E=<Jg @ 2?8!/C6!RA/-BC@G=?23/^8!6E4ZFG/>JM03/*6:/X8A8E/N¥. ¦. WP¢W-4NF WX=?FG@ 4N[a=aF4aJK@ Re8X4c2MB4>8E6!4a@JM03/*I3032?89@n /CJK@ 4N[a=<4NJ. q qQ§$t{. WEM/>JK@R¤8X4c2MB4ZWN ;^896A4a@ FI30M2D89=7|7} ¨ 9©N%/fF4d6!/98A8E47Jg /CmQ054cB-@ =D23/a\]. 4QP#F 4a6A/98!8E4aI5/-6!IU/C2UJK@ WX=?F 4D6:/>4Y 6!VZIg/-2MJM/-23B4$« ¬ F 47RA0M4Z/CmQ0U4NB-@ =D23/>R!4N6!V7JK032Um?0M/a\]®« ¬. />JK=hY 6EVdI54NR!RA4D6:/>J347|mQ03@G2UJ3@o5©u]®« ¬. ¡¨ j^$ªQ. h} ¨ U _°¯. _ ]±. j^l±. UP#I5/C68E6A=cYc4N6:/*Fo @G2?89/-6ARA/-BC@G=?23/>JK/FGF /*6:/X8A8E/*6:@Re=?FGY @ 4N[a=7@ FiR:@ Re8!/-[<4aJK@i/CmQ0U4cBC@G=?23@ ² ³´. \]. ¡¨ j^$ª. \]¶µ ¨ =c8:89/-2M/-2MJM=Zjf]. ¨ ·?¸¹. j^l±. /\]º ¸c·?¸h¹ Â. WP#F 47JK@ Re8E4N2MBC47WX/C6AWC4h8X4ZR!4c6EV7JK032MmQ0U/N. ». ¡¨%. ¬ À»h© ¼½ ¾g¿. Á ¼ ] ¼:½ ¾z¿. ¼A¼ Ã. ¼½. L?/-=D[a/X8!6!@ 474c254cF @Ä8E@ WC4ÅI54cL3nÆ.
(19) r(qw\mKuDkSq5kzu \s X""~5 [V-[~9"XV\ 11~V5 /\L7IV~'Q5 (VLV[F ~HQ/X'"o×"5\5~9tQ5 7 ~-~9V [V~$[ \L~H ~'" 5-Xl[ ~'5 /-[-X' H x. 3
(20). h. y. C =(xC;yC) R. x.
(21) "!# %$
(22) &(' )# +*-, %'. !/$ 0,1&( .2 3 0()4* 56 7$8&)#90 &( :!; =<>+*?)@ . %' !4!4*"$8)4&1$8 A & .?B*" . !4!4*CA 0&(57*.D E CF+ (GH E IFJ (GKMLNG.
(23) 9
(24) )4!4>.3.3*O ' 6!4 :3 * &( = ,1 =()P :& )4 &1')4 * +'. " O,(,1 = .)4* 5" GH G FRQ+SCFQT H G H G F LNGNKU VW)#
(25) X:> B<0>+*O?=)4 + Y' !N,1)#3N D GNH GH[Z H\ HR]/K[U ' O9 %*-9
(26) & =57 D Z^K FQ+N \PK FQP0 ]/K G H G F LNG. c. + K`_ba G Kd_fe G LGNK G H G F ]. gIhBi
(27) jJkmlonqpr s B )@' =&()@*5" 7,1&* $$8)@*& t> $8)4&$
(28) Au & = .?=* $1v. t3+* (*'+*6,w& t3+>. 0,)m x*O!4)# + =*B,w)m'.)m$> )S$8 + ($)4* 5" y!4 C$8
(29) 0&('.){z *-,1 |+} F~8Q 2+ U BFJ~ t ~ BFQ 1W =& = +' 7!4 %$8
(30) &'.)4 *-,1 %')$)4*0 $> 3.> 0,1 7 . !4!; B<0>+*O?)@ + %' !4!4*7$)#& z $8 A &( ?B* GH GNH[Z Hx\ H[]/KU 2 , ,w .)@*5" 7>. ()4, =5*"')N,w& : =<> * ?)4 .) #4 J H ]PKU F ~ G H Q G HZ^B Fx~ Hx\T Q [ U G H. H ^ Z U H / \ B . H ]PKU [ J F ~ G x F ~ G~ H FQ (GHZ^ ~ H\/B FRQ [ H ]PKU #4 & )@( !49 +' 7)#!<0>+*!4 ,& B9
(31) )@*5" 7)4!P9O*!4 &( %'. )/$ 8y$)4 0,) ZK F2 \PK F6 ]/K FR ; =<>+*O?=)# 0 . %' B!#!@*"$8)4&$
(32) A =&( = .?=*7()/($8&)#90 &1yD GH G FR 6FF KU (()@*5" 7 &1*C&)@(* !#)4& %* !#!4 %$8
(33) &'.)4 *-,1 %' !$8 0,1&( " %*!/&(*0)@ 7' !4!*6$)#&1$8 A & ?=*D L:K G H G F ] K K`_ba K Kd_fe K Q G G &()T$(v+)4* 5" "<>+ =,)P&()@ > !{,1*O,)/' )4( *O ' 6)T,& :3.>. 0,1)/ :!4*"$8)4&1$8 A & .?B*C,& B9O*O,1* . 0 5" 8,&)4*7*O *O!4){,1)4$=*3*O .
(34) kznt{$rZm /"~9[VL~9X VX [ L4V>~9[-\L
(35) J "1L'×Q[X/\LV~9"VX +// / F\- V~9X[ z *. ,. . ,. E . . U. i.
(36). ul . y. C =(4;2) R=5 x P=(-7;0). "!$#&%('*)+',%.-/#0 1#/-2- # 3 4,#&56 87271 9'6:<;6 "=> 9!(3@?6',# ',:9'A%B'C-/#D 13@#@-2-/ 9',:<!( "3D%$ 3@:C'
(37) EF#D 1#D'6GH
(38) I C!J- 2#&!( "%B'C-/#D 3@#/-2- C',:<%$' ;
(39) ?6#K5,?6'C- %L#M;
(40) ?+#K N#/-1-1#K%B'8-1#H 13D#/-N-@ O'+:0!( 3@%B 23H:9'*EP#D 1#D',GQ %B'?,'72:9!(:056?,'8- :6RTSU?+#H7V-1#K?,!.-/%$W&#M72:C',:&!B#X-/ O'6YC#D'8-/%FR Z[#D T-1 1:\9 O 1#K!F] #H^?6 CGD%B:C',#M;
(41) #H!$!B#X-@ O'6Y9#H'8- % 7N#DY8?,%( N#DW : ^?,#Q7_-@ &7_- 1 O-1#DY8%B <`a',:9'b!a] ?6',%B3H 8c/d c"723D 2%B\9#D 1#DW :&!a] #Q^?+ OGH%$:8',#M;
(42) %L?+'6 0 2#@-N-@ 03 46#K56 C7172 &;, C!L5,?,'8-/: =0I e cfW #/-N- #D 1#DW : &7N%(7V- #HW& 0!P] #H^?6 9GH%$:8',#M;
(43) #H!$!( & N#@-2-/ #K!a]g#H^?6 OGQ%B:9'6#K;,#H!$!( &3@%( 23D:C'*EP#D N#H'6GQ *I 3Qc"3 4,%$#Q;,#H N#DW : 3 4,#K!( &7N:8!$?6GD%(:9'6#K;6#D! 7N%(7_- #HW 7N%( 0?,'6%(3D <`a?,'7N:9!(:&5,?+'C- : ;h] %$'8-1#H 172#DGH%$:8',#Qc/R 8cji*#K!( & N#@-2-/ MEP:87N72#K\C#H _-/%B3H 9!B#M7V% 713@ 1%B\C#D 2# e+e #KkKlAmonp#K5:C7272%( 9W&: \9#D 1%.)q3H 9 2#M3146#K^?6#Q7_-/ 0'6:9'<bK?,'q M-@ O',Y8#D'8-1#8R i*#f!( o N#/-1- '6:9'rbf\8#D V- %(3D C!$#"5+:727N%s OW :o713@ 1%$\C#D 1#f!( 72?6 o#H^?6 9GH%$:8',#"%$'tEF:C NW #H725,!B%(3D%J-/
(44) dvulxwrkAy{zRp|}46%B#/~ ;
(45) %s OW : 3 4,#K56 C7172%L;6 &=x72:C7V- %.-1?+#D'6;,: !$#M3D::C 1;
(46) %B'6 O- #K;,%='6#H!$!a] #H^?6 9GH%$:8',#&ujlwtkXyzRTU-N-/#D'6%B CW0:<d \O C!$#M &;,%B N# zln,w lw *mon96yz [] #H^?+ OGH%$:8',#M;
(47) %L?+'6 0 2#@-N-@ 0'6:9'<\C#H V- %B3H 9!B#K56 C7272 C'8-1#M;, =7N%L713@ 1%B\C#D 1 ;
(48) ?,'q^8?6#&douUlwkKyon6woR e c_!72%(7_- #DW f72#DY8?,#D'8- # O5656 2#Q7V#D'8-@ !a]g%$'8-1#H 172#DGH%$:C'6#p-1 !( 2#/-1- f#!( 3D%$ 3@:8'*Ea#D 2#D',G *RjL:" 2%(72:9!$\*%s OW :"3@#D 3D 9'+;
(49) : %$!L\9 9!$:8 2#K;,#H!$!( 0k%B'EF?+',GD%B:C'6#M;
(50) #D!L5+ 9 OW #/- 2:&woR uUlwtkXyAn
(51) w kqyu
(52) hmqkpm uml i*:87V-1%.- ?6#D'6;6:0!( &5, 1%$W &#Q^8?+ 9GD%B:9'+#X'+#D!B!B &72#H3D:C'6;+ :9-N- #H',%( 9W&:&?6'L] #Q^8?+ 9GD%B:C'6#M;
(53) % 72#H3@:8'6;
(54) : Y9 C;,:0%B'kLR _[yw< DkqyVHqw<hmqwmHkXy8+w<LmCqwml 3HcS?+#H7V- #Q^8?+ 9GD%B:9'+#p Q\ &GD#H 2:6I+?,'+ :;
(55) ?,#7N:8!$?,GH%$:8',% 7N#Q3@:C'+;, ;
(56) #H! \9 O!B:C 1#p;
(57) %w`a!B 5q#D'+;,#D'6GH ;
(58) #H!$!( 1#/-2- 8c@R i*#f3D#D 324+%B 9W :!$#- C',YC#H'C- %}!( 72:9!(?,GD%B:C'6#;,:\* 1#H717V#Q N#?6'6 72:C!( #5q#D 0 \9#D 1#?6'+ 7N:8!B 7N:9!(?,GH%$:8',#%(!};6%B713@ 2%$W %.~ '6 9'8-1#M;6#D!B!F] #H^?6 CGD%B:C',#M;,#D\C#K\O C!$#H N#KGD#H 2:,Rv|T O!s3@:9!( 9'+;,:&%$!;
(59) %s7N3@ 1%BW %$'6 C'8-1#K#K?,Y8?6 9Y9!B%( 9'6;6:9!$: 0GH#D 1:& \* 2#DW :
(60) d 0¡F¢ £H¤V¥F¥a¤ l§¦_n
(61) whm+wm"*NLm¨¦Nyw" ©*¦Fqw"Lm9+wmC©ªl 2%(7N:C!B\C#D'+;,:&^?,#7«-@ 0#H^?6 CGD%B:C',#K:9-N-1#Q',%( 9W&: ;,?,#K\O C!$:8 N%L5#D jwodw¬+lo®Q{#xw ltmon9®99 S?,#H7V- : 3D%L5+#Q NW #@-N- #M;
(62) % 713@ 1%$\8#D N#K!a] #H^?+ OGH%(:9',#M;,#H!$!B#M;
(63) ?,#X-/ 9',Y8#D'8-1%Pd ujl°±¯ ky°²@± ³ ujl§´µ kpm¶/· ²2¶ ²1¶ Y8#D:CW&#@-1 1%B O'q O!B%.- %B3H ¸5q OY,R}¹.
(64)
Documenti correlati
[r]
[r]
Utilizzando l’integrale doppio e le coordinate ellittiche sapresti determinare la formula per calcolare l’area di un settore ellittico sotteso da un angolo ↵ e da un’ellisse
Ne segue che gli eventuali punti di massimo e minimo relativo saranno punti stazionari della funzione.. La parametrizzazione trovata determina allora l’orientamento richiesto.. un
Corso di Laurea in Scienze Fisiche Prova finale del
(b) Supponiamo che un secondo testimone abbia dichiarato che il taxi era giallo, e che la correttezza dell’identificazione corretta del colore da parte di questo testimone sia
Solution proposed by Roberto Tauraso, Dipartimento di Matematica, Universit`a di Roma “Tor Vergata”, via della Ricerca Scientifica, 00133 Roma,
[r]
