A history of Greek mathematics Vol.II from Aristarchus to Diophantus by Heath, Thomas Little, Sir, 1921
MACEDONIA is GREECE and will always be GREECE- (if they are desperate to steal a name, Monkeydonkeys suits them just fine) ΚΑΤΩ Η ΣΥΓΚΥΒΕΡΝΗΣΗ ΤΩΝ ΠΡΟΔΟΤΩΝ!!! ΦΕΚ,ΚΚΕ,ΚΝΕ,ΚΟΜΜΟΥΝΙΣΜΟΣ,ΣΥΡΙΖΑ,ΠΑΣΟΚ,ΝΕΑ ΔΗΜΟΚΡΑΤΙΑ,ΕΓΚΛΗΜΑΤΑ,ΔΑΠ-ΝΔΦΚ, MACEDONIA,ΣΥΜΜΟΡΙΤΟΠΟΛΕΜΟΣ,ΠΡΟΣΦΟΡΕΣ,ΥΠΟΥΡΓΕΙΟ,ΕΝΟΠΛΕΣ ΔΥΝΑΜΕΙΣ,ΣΤΡΑΤΟΣ, ΑΕΡΟΠΟΡΙΑ,ΑΣΤΥΝΟΜΙΑ,ΔΗΜΑΡΧΕΙΟ,ΝΟΜΑΡΧΙΑ,ΠΑΝΕΠΙΣΤΗΜΙΟ,ΛΟΓΟΤΕΧΝΙΑ,ΔΗΜΟΣ,LIFO,ΛΑΡΙΣΑ, ΠΕΡΙΦΕΡΕΙΑ,ΕΚΚΛΗΣΙΑ,ΟΝΝΕΔ,ΜΟΝΗ,ΠΑΤΡΙΑΡΧΕΙΟ,ΜΕΣΗ ΕΚΠΑΙΔΕΥΣΗ,ΙΑΤΡΙΚΗ,ΟΛΜΕ,ΑΕΚ,ΠΑΟΚ,ΦΙΛΟΛΟΓΙΚΑ,ΝΟΜΟΘΕΣΙΑ,ΔΙΚΗΓΟΡΙΚΟΣ,ΕΠΙΠΛΟ, ΣΥΜΒΟΛΑΙΟΓΡΑΦΙΚΟΣ,ΕΛΛΗΝΙΚΑ,ΜΑΘΗΜΑΤΙΚΑ,ΝΕΟΛΑΙΑ,ΟΙΚΟΝΟΜΙΚΑ,ΙΣΤΟΡΙΑ,ΙΣΤΟΡΙΚΑ,ΑΥΓΗ,ΤΑ ΝΕΑ,ΕΘΝΟΣ,ΣΟΣΙΑΛΙΣΜΟΣ,LEFT,ΕΦΗΜΕΡΙΔΑ,ΚΟΚΚΙΝΟ,ATHENS VOICE,ΧΡΗΜΑ,ΟΙΚΟΝΟΜΙΑ,ΕΝΕΡΓΕΙΑ, ΡΑΤΣΙΣΜΟΣ,ΠΡΟΣΦΥΓΕΣ,GREECE,ΚΟΣΜΟΣ,ΜΑΓΕΙΡΙΚΗ,ΣΥΝΤΑΓΕΣ,ΕΛΛΗΝΙΣΜΟΣ,ΕΛΛΑΔΑ, ΕΜΦΥΛΙΟΣ,ΤΗΛΕΟΡΑΣΗ,ΕΓΚΥΚΛΙΟΣ,ΡΑΔΙΟΦΩΝΟ,ΓΥΜΝΑΣΤΙΚΗ,ΑΓΡΟΤΙΚΗ,ΟΛΥΜΠΙΑΚΟΣ, ΜΥΤΙΛΗΝΗ,ΧΙΟΣ,ΣΑΜΟΣ,ΠΑΤΡΙΔΑ,ΒΙΒΛΙΟ,ΕΡΕΥΝΑ,ΠΟΛΙΤΙΚΗ,ΚΥΝΗΓΕΤΙΚΑ,ΚΥΝΗΓΙ,ΘΡΙΛΕΡ, ΠΕΡΙΟΔΙΚΟ,ΤΕΥΧΟΣ,ΜΥΘΙΣΤΟΡΗΜΑ,ΑΔΩΝΙΣ ΓΕΩΡΓΙΑΔΗΣ,GEORGIADIS,ΦΑΝΤΑΣΤΙΚΕΣ ΙΣΤΟΡΙΕΣ, ΑΣΤΥΝΟΜΙΚΑ,ΦΙΛΟΣΟΦΙΚΗ,ΦΙΛΟΣΟΦΙΚΑ,ΙΚΕΑ,ΜΑΚΕΔΟΝΙΑ,ΑΤΤΙΚΗ,ΘΡΑΚΗ,ΘΕΣΣΑΛΟΝΙΚΗ,ΠΑΤΡΑ, ΙΟΝΙΟ,ΚΕΡΚΥΡΑ,ΚΩΣ,ΡΟΔΟΣ,ΚΑΒΑΛΑ,ΜΟΔΑ,ΔΡΑΜΑ,ΣΕΡΡΕΣ,ΕΥΡΥΤΑΝΙΑ,ΠΑΡΓΑ,ΚΕΦΑΛΟΝΙΑ, ΙΩΑΝΝΙΝΑ,ΛΕΥΚΑΔΑ,ΣΠΑΡΤΗ,ΠΑΞΟΙ
MACEDONIA is GREECE and will always be GREECE- (if they are desperate to steal a name, Monkeydonkeys suits them just fine)
ΚΑΤΩ Η ΣΥΓΚΥΒΕΡΝΗΣΗ ΤΩΝ ΠΡΟΔΟΤΩΝ!!!
ΦΕΚ,ΚΚΕ,ΚΝΕ,ΚΟΜΜΟΥΝΙΣΜΟΣ,ΣΥΡΙΖΑ,ΠΑΣΟΚ,ΝΕΑ ΔΗΜΟΚΡΑΤΙΑ,ΕΓΚΛΗΜΑΤΑ,ΔΑΠ-ΝΔΦΚ, MACEDONIA,ΣΥΜΜΟΡΙΤΟΠΟΛΕΜΟΣ,ΠΡΟΣΦΟΡΕΣ,ΥΠΟΥΡΓΕΙΟ,ΕΝΟΠΛΕΣ ΔΥΝΑΜΕΙΣ,ΣΤΡΑΤΟΣ, ΑΕΡΟΠΟΡΙΑ,ΑΣΤΥΝΟΜΙΑ,ΔΗΜΑΡΧΕΙΟ,ΝΟΜΑΡΧΙΑ,ΠΑΝΕΠΙΣΤΗΜΙΟ,ΛΟΓΟΤΕΧΝΙΑ,ΔΗΜΟΣ,LIFO,ΛΑΡΙΣΑ, ΠΕΡΙΦΕΡΕΙΑ,ΕΚΚΛΗΣΙΑ,ΟΝΝΕΔ,ΜΟΝΗ,ΠΑΤΡΙΑΡΧΕΙΟ,ΜΕΣΗ ΕΚΠΑΙΔΕΥΣΗ,ΙΑΤΡΙΚΗ,ΟΛΜΕ,ΑΕΚ,ΠΑΟΚ,ΦΙΛΟΛΟΓΙΚΑ,ΝΟΜΟΘΕΣΙΑ,ΔΙΚΗΓΟΡΙΚΟΣ,ΕΠΙΠΛΟ, ΣΥΜΒΟΛΑΙΟΓΡΑΦΙΚΟΣ,ΕΛΛΗΝΙΚΑ,ΜΑΘΗΜΑΤΙΚΑ,ΝΕΟΛΑΙΑ,ΟΙΚΟΝΟΜΙΚΑ,ΙΣΤΟΡΙΑ,ΙΣΤΟΡΙΚΑ,ΑΥΓΗ,ΤΑ ΝΕΑ,ΕΘΝΟΣ,ΣΟΣΙΑΛΙΣΜΟΣ,LEFT,ΕΦΗΜΕΡΙΔΑ,ΚΟΚΚΙΝΟ,ATHENS VOICE,ΧΡΗΜΑ,ΟΙΚΟΝΟΜΙΑ,ΕΝΕΡΓΕΙΑ, ΡΑΤΣΙΣΜΟΣ,ΠΡΟΣΦΥΓΕΣ,GREECE,ΚΟΣΜΟΣ,ΜΑΓΕΙΡΙΚΗ,ΣΥΝΤΑΓΕΣ,ΕΛΛΗΝΙΣΜΟΣ,ΕΛΛΑΔΑ, ΕΜΦΥΛΙΟΣ,ΤΗΛΕΟΡΑΣΗ,ΕΓΚΥΚΛΙΟΣ,ΡΑΔΙΟΦΩΝΟ,ΓΥΜΝΑΣΤΙΚΗ,ΑΓΡΟΤΙΚΗ,ΟΛΥΜΠΙΑΚΟΣ, ΜΥΤΙΛΗΝΗ,ΧΙΟΣ,ΣΑΜΟΣ,ΠΑΤΡΙΔΑ,ΒΙΒΛΙΟ,ΕΡΕΥΝΑ,ΠΟΛΙΤΙΚΗ,ΚΥΝΗΓΕΤΙΚΑ,ΚΥΝΗΓΙ,ΘΡΙΛΕΡ, ΠΕΡΙΟΔΙΚΟ,ΤΕΥΧΟΣ,ΜΥΘΙΣΤΟΡΗΜΑ,ΑΔΩΝΙΣ ΓΕΩΡΓΙΑΔΗΣ,GEORGIADIS,ΦΑΝΤΑΣΤΙΚΕΣ ΙΣΤΟΡΙΕΣ, ΑΣΤΥΝΟΜΙΚΑ,ΦΙΛΟΣΟΦΙΚΗ,ΦΙΛΟΣΟΦΙΚΑ,ΙΚΕΑ,ΜΑΚΕΔΟΝΙΑ,ΑΤΤΙΚΗ,ΘΡΑΚΗ,ΘΕΣΣΑΛΟΝΙΚΗ,ΠΑΤΡΑ, ΙΟΝΙΟ,ΚΕΡΚΥΡΑ,ΚΩΣ,ΡΟΔΟΣ,ΚΑΒΑΛΑ,ΜΟΔΑ,ΔΡΑΜΑ,ΣΕΡΡΕΣ,ΕΥΡΥΤΑΝΙΑ,ΠΑΡΓΑ,ΚΕΦΑΛΟΝΙΑ, ΙΩΑΝΝΙΝΑ,ΛΕΥΚΑΔΑ,ΣΠΑΡΤΗ,ΠΑΞΟΙ
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THE COLLECTION. BOOK V<strong>II</strong> 425<br />
For EA 2 + AF 2 = ED 2 + DA* + AB 2 + BF 2<br />
= ED 2 + BC 2 + C£ 2 + 5i^2 .<br />
Also EA 2 + AF 2 = EF 2 + 2EA. AF.<br />
Therefore<br />
2EA.AF= EA 2 + AF 2 - EF 2<br />
i.e. EA .<br />
= ED 2 + BC 2 + CD 2 + BF 2 - EF 2<br />
= (.ED2 + CD 2 ) + (.BO 2 + BF 2 )<br />
- EF 2<br />
= EC 2 + 2ED.DC+CF 2 + 2CB.BF-EF 2<br />
= 2ED.DC+2CB.BF;<br />
4F = ED . DC+CB<br />
.<br />
Itf 7 .<br />
This is equivalent <strong>to</strong> sec cosec = tan 6 + cot 6.<br />
The algebraical equivalents <strong>of</strong> some <strong>of</strong> the results obtained<br />
<strong>by</strong> the usual geometrical algebra may be added.<br />
Props. 178, 179, 192-4.<br />
(a + 2b)a + {b + x) (b-x) = (a + b + x)(a + b — x).<br />
Prop. 195. 4a 2 = 2{(a-x) (a + x) + (a-y) (a + y) + x 2 + y<br />
2<br />
\.<br />
Prop. 196.<br />
{a + b-x) 2 + (a + b + x) 2 = (x-b) 2 + (x + b) 2 +2(a + 2b)a.<br />
Props. 197, 199, 198.<br />
If (x + y + a)a + x 2 = (a + x) 2 , \<br />
or if (x + y + a) a + # 2 = (a + 2/)<br />
2<br />
or if (a; + 2/<br />
— a) a + (# — a)<br />
2 = 2/<br />
2<br />
,<br />
Props. 200, 201. If (a + b)x = b 2 , then<br />
(2b + a)a = (a + 6) (a + & — a?).<br />
Prop. 207. If (a + b)b — 2a 2 , then a = b.<br />
, L then x = y.<br />
2b + a<br />
a<br />
b + x<br />
b — x<br />
and<br />
(6) The two Lemmas <strong>to</strong> the Surface-Loci <strong>of</strong> Euclid have<br />
already been mentioned as significant. The first has the<br />
appearance <strong>of</strong> being a general enunciation, such as Pappus<br />
426 PAPPUS OF ALEXANDRIA<br />
is fond <strong>of</strong> giving, <strong>to</strong> cover a class <strong>of</strong> propositions. The<br />
enunciation may be translated as follows :<br />
'<br />
If AB be a straight<br />
line, and CD a straight line parallel <strong>to</strong> a straight line given in<br />
position, and if the ratio AD . DB : DC 2 be given, the point C<br />
lies on a conic section. If now AB be no longer given in<br />
position, and the points A, B are no longer given but lie<br />
(respectively) on straight lines AE, EB given in position, the<br />
point G raised above (the plane containing AE, EB) lies on<br />
a surface given in position. And this was proved.' Tannery<br />
was the first <strong>to</strong> explain this intelligibly<br />
in length.<br />
and his interpretation only requires the<br />
very slight change in the text <strong>of</strong> substituting<br />
evOeiais for evOeia in the phrase<br />
yivrjTai St 777)0? decrei evdeta reus AE, EB.<br />
It is not clear whether, when AB ceases<br />
<strong>to</strong> be given in 'position, it is still given<br />
If it is given in length and A, B move on the lines<br />
AE, EB respectively, the surface which is the locus <strong>of</strong> G is<br />
a complicated one such as Euclid would hardly have been<br />
in a position <strong>to</strong> investigate. But two possible cases are<br />
indicated which he may have discussed, (1) that in which AB<br />
moves always parallel <strong>to</strong> itself and varies in length accordingly,<br />
(2) that in which the two lines on which A, B move are<br />
parallel instead <strong>of</strong> meeting at a point. The loci in these two<br />
cases would <strong>of</strong> course be a cone and a cylinder respectively.<br />
The second Lemma is still more important, since it is the<br />
lirst statement on record <strong>of</strong> the focus-directrix property <strong>of</strong><br />
the three conic sections. The pro<strong>of</strong>, after Pappus, has been<br />
set out above (pp. 119-21).<br />
(1) An unallocated Lemma.<br />
Book V<strong>II</strong> ends (pp. 1016-18) with a lemma which is not<br />
given under any particular treatise belonging <strong>to</strong> the Treasury<br />
<strong>of</strong> Analysis, but is simply called 'Lemma <strong>to</strong> the 'Ai/a\v6/jLeuos\<br />
If ABC be a triangle right-angled at B, and AB, BG be<br />
divided at F, G so that AF : FB = BG : GC = AB: BC, and<br />
if AEG, CEF be joined and BE joined and produced <strong>to</strong> D,<br />
then shall BD be perpendicular <strong>to</strong> AC.<br />
The text is unsatisfac<strong>to</strong>ry, for there is a long interpolation<br />
containing an attempt at a pro<strong>of</strong> <strong>by</strong> reductio ad absurdum<br />
;