1 3(3 
3NJ R. HEARN ON A CLASS OF PARTIAL DIFFERENTIAL EQUATIONS. 
Inserting- these values in the final formula, we have 
/ V X 
cos 2n — xydy+M, 
and 
u 
=/ 
y—% r -iV~ x i i 
cos — — J cos .... v n dydy . . 
2 J 2 
which agrees with Mr. Hargreave’s solution. 
. n times, 
