( 492 ) 
T,=3T;. But for y=0 or n=1 the first member = 0, and the 
second =—1. So there is a value of y, for which 7, = 7; and of 
course this value must be larger than that which we found above, 
2 
dy .. 
— disappears 
de 
when we determined for what value of y the curve 
2 
dp 1 
a= 0. So if we put cs the first member 
D 
on the boundary of 
52 
is equal to 1, and the second to re: The equality of the two members 
requires y about 0,36, to which n= 3.7 corresponds, which is but 
little greater than we found above for the smallest value of 7 for which 
d? d* 
x = 0 goes beyond mt a 
dx? dv? 
For the tangent for which a == 0, the condition becomes: 
a Sd Se 
ee ai (1—y) 
We cannot expect another ise for the points of the tangent than 
1 ’ : 
Ie The last inequality may also be written : 
0 2 (1—2y)* (1 + 4y + 10y? + 9) 
