376
A MEMOIR ON CUBIC SURFACES.
[412
then the equations of the planes are:
W= 0,
lX + mY + nZ + W
X Y Z
—í—b h h YÍ
i m n
1+ lH)Kw
'^sHK—á
n--
n
n--
n
X=0,
Y= 0,
Z = 0,
X + j fm — —) in — If = 0,
fc \ ml \ n)
r+ i(—i)( , -l) ir -*
z + l{ l ~ =
IX + -+ z +w=o,
m n
y +mY+ —+TT=0,
l n
Y V
T + -+ Z+ w= 0,
l m
-j + mY + nZ + W = 0,
IX + - + nZ+W = 0,
m
lX + mY+ - + W = 0,
n
z ;(p-g) + 2mn
P + ß
y i M(p-«)+2nl w _
+ p + ß n - V ’
n(p-a) + 2lm
+ p + ß
1 / x 2
T (p - a) -\
x + l rr^W=0,
p + ß
1 / x 2
m (p ~ a) + ñl
Y+- W = 0,
P + ß
i/ N 2
2'+- —ti W=0,
P + ß
[12' = w]
= 0, [23' = 0]
= 0, [31' = 0]
[12.34.56=«]
[42' = y]
[14' = s]
[21' = £]
[32'= 77]
[13' = n
[41' = f]
[34' = g]
[13.24.56 = h]
[24' = f]
[14.25.36 = g]
[43'= h]
[12.35.46 = x]
[52' = y]
[15'= z]
[12.36.45 = x]
[62' = y]
[16' = z]