IN THE STUDY OF ANALYSIS. 



39 



inclinations and intersections of lines and planes, for both right 

 and oblique axes. 



(10.) The properties of the conic sections are easily remem- 

 bered, when the student has learned to talk to himself about 

 them in rapid and unambiguous syllables like the following. 

 The equation to the central conies being— 

 a:' I y^ — 1 



the following mnemonics are a few examples out of many. 



[Pron. (1 d), un d, a dissyllable.] 



Sq}- is SUD (1 e) SUP (d x) ;* 



2 squib's larec h, ; per (ab) is ek ; 



at or* foe the x* is ea mol x\ 



6rfoc, r's larec by ('2 mo 2 eco^) : 



h mol ex or ex mol a 



are fops in 'li'pse or hyT)ola : 



diet is ba by mean fops : 



dift is b' of ro6q fops, 



and b' is mean of difts : 



ba by diet is cbnja : 



mean of fdps is cbnja : 



rho. ba is cu conjk j 



rho ba is cuper (a ex) : 



per (poc 'b) is xb. 

 (a.) y* = (1 — c«) («' — a:^) 

 (J.) 26^ rr /a, ? being larec, or /atus rectum : (a^ — J')* zr ea. 

 (c.) The origin is at the^cus, when the equation is — 



a^ * b^ 



mo ia + under a lincnlnm. 



'^ 2+2ecos. ^ 



(c.) (a + ex) are the distances from j^ci of a point p, or the 

 fops, in the ellipse, and (jex + a) the^ps in the hyper- 

 bola. 



if.) diet is rftstance of centre from fengent, and rr ha'. 

 (a* — e* a:^)*, or 5a by mean of fops, zz ba : (^)*, if 

 /and/' are fops. _ - 



