nes ail des ESF Bh veiw aise swiveeesesssans 2 acar6s ae are Wedriucle — < ag -—7 pe 4, Note on Professor Tait’s ‘“‘ Quaternion Path” to Deter- minants of the Third Order. By the Rev. Hugh Martin, M.A. Communicated by Professor Kelland. I have read with much interest Professor Tait’s ‘“‘ Note on Deter- minants of the Third Order” in the Proceedings of this Session (pp. 59-61), and admire the method of discovering new proper- ties of Determinants. I am not sure, however, that the properties, when discovered, are more difficult of proof by Determinant methods, and I venture to submit the following as simple and elementary :— The first property, namely, ete, y ty 2+%|=2 He YAY 4% te y+y +2 is true under greater generality, and the Determinant proof is the same as for the special case. VOL. VI. »41950 Proceedings of the Royal Society ° ‘ S1OYJO OY} JO YOVO WOT MOL SIF MOU SUI}[USEI OTT} JORAIQNS : yUvUTTIOJOP OY} OpIsyno (T—u) OJON oy} Oye , uly po: stp (qu) ie: OTD see +1 +(q-u) ‘ATOUVU ‘MOL ISIE MOU B WIOJ OF SMOI OY} [IP PPV xt aos —u* —u' 5) ut ce Op ee ot Pees ee eee ik 0 ware ae: yee Se 10) ° ° e e e e e e e ° e e ° ° ¢ e ° 4 e e e e ° ° e ° ° ° ° e ° e . eo e e ° e e ° e e e e e e e (4 . . ¢ ° e ° ° e ° ° of Edinburgh, Session 1866-67. 123 then add to it the sum of the others: and we have =(n-1 “ves ¥ ( ) Oe Cn Cn a eens Br to 1 cy Ont ie oa g 7 ay 9 Ki a, 2 or 6 ay is a Poe ah std Sasa: oe The negative signs may be removed and compensated for by the factor (—1)"—' placed outside the Determinant, and the first row may be made the last by multiplying again by (—1)"—', which counteracts the former multiplication. Hence V=(n-1) @.7 % 1° oar a, When n=3, this is the quaternion theorem in question. The second formula is the well-known property of the reciprocal, and a simple proof of it will be given below. The third and fourth are immediate translations of Quaternion expressions into Determinant forms. And I suppose there is no analytical difficulty in enlarging the number of Sir William R. Hamilton’s symbols, 2, 7, & (though it would introduce the concep- tion of ideal space of more dimensions than three), and thus ex- tending the reach of the “ Quaternion path” to Determinants of any order. The jith formula, in its algebraical expression, would be y2z2i|e | y, 2, ze |+| 2%, & = —-2|u yz |? Y By Y¥2 oP) aN w oP) , ‘ FS w, 4, a a Ya Be 9% | F | YY 4, & & 7 Yo %, ET x, ms Y.% | bly % ye ye, |? Ce &e. 124 Proceedings of the Royal Society Now, using capitals for minors we have, by the first property, Sak Y.42y. vee 2[ Xi Bea Ko RY YZ ee xX, ae X, +X Yt Y, Z+4Z, 2 cea a PR a —2\o 9 2 = XA = © i ae Q. E. D. Ay Xe Ay %, Y, %, This, of course, may be generalised like the first formula; and the result is se + ee De rae . +A, 9: &., &e. ee ao Ae A. at : +A Ue &e., &. ae bt AD h A, ih ° FA, » &.; &C. n / Ai ig ye Ay or A, i+ ; = A &c., &e. (es —1 (n — 1) Oy ig Sir 4) n oe . e e ea The sixth formulais got by a reduplication of the proof of the Jifth,whether the method used be Quaternion or Determinant. As to the reciprocal, the following seems quite elementary :— Let Y%, — 24, 2h, — LZ, LY, — YX, Yi%, — 2 Yn 20, — U2, VY, — YX |= 4 Ye — ay Be — m2, BY — Y~ Multiply the first row by «,, the second by a, the third by w,; add all the rows for a new first row; divide the second row by @, and the third by «,. q 9% £, Y, 2, 0; 33920 £9 2 = %,V xX Vigo 4 X, Vee: of Hdinburgh, Session 1866-67. Hence Pat YS wv, Yi zy y z,\=%¥ Be Oates itis But it is at once seen that le a, 4, # 1 1 1 af ZL, ® Y, % Hence ae y ¢ |? ae Bee Fee. 5 Q. KE, D $. Y, %, So bo a sore ey bee f Makers Syracuse, N.Y. | PAT. JAN. 21, 1908 Gaylord Bros. Oye: <8 . . sped Ral ke » ‘ 33 mae oa ae em ah et a ee (est de awew ans teens ene we awte Sere ee see nwa we Pose awsnse se. 512.53T13NYM C001 NOTE ON PROFESSOR TAIT’S QUATERNION PATH LE 3 0112 0170573