I 1 14 A.\S\i'ER8 



39. -+-.. 40. 



41. No. 42. x 2 + y'+10z + 10y = 86,or*a + y*-8x--20y + 31 =0. 



43. 2x-3y= 1.% 2y + 3x = 0; f = Vf|x + 6, x = 0. 



44. y -8 = 49d v^(x-2). 45. 46. 



to 



46. F.quation of diameter IB 6x+4y = l, equation of chords is 5y=4x+fc. 



47. x* -f y = n -f r a *. 



48. The locus is the circle (x-JCi)* + (y-y,)* = *a[(x-x,)-.(y-y,)a]. 

 60. The condition that these circles cut each other at right angles is 



J ffi0i : -J /-',F, = Ci + C 2 . 



Page 175. Art. 106. 



1. 25 x* + 30 xy -f y* -f 80 x - 224 y + 336 = 0. 



2. .r- + 4xy + 4y*-12x + 6y-9 = 0. 8. y* = 12x. 4. x = -12y. 

 5. jr' + 4x + 16y = 76. 6. y + 8y-12x = 8. 7. y = 4p(x-p> 

 8. 12; 12; 16; 12. 



Page 177. Art. 107. 



; 5; 20x + 81=0; y + 2=0. 



2. (-2,6); ("2, V)J *; 3y = 16; x + 2 = 0. 

 3- (II, $); (ft< J);{;48x = 20;6y = 5. 



4. (-1, -1); (2, -1); 12; x -f 4 = ; y + 1 = 0. 



Page 178 Art. 108. 



L * = 12- . f. y = -JL x . 3. 



V34 V63 



Pages 185. 186 Art. 112. 

 1. 7x + 2xy + 7y+10x-10y + 7=0. . Sx 2 + 9y - 18x = 81. 



3. 26 x -I- 24 y = 000. 4. ^ + ^ = 1 ; latus rectum = --. 



6. 



+ = i 9 + -=1. lO^ 



81 + 46 26^20 81 



