T'Xr-aT(X'Y+Xr=0 TX Y n rthy=o m=sin aTX Y b T X"+∠X=0 +h SIn T"(+p)a2T=0 T(t)=exp(nI+m23 a t' ( '' '') 0 2 T XY − a T X Y + XY = − = = − Y Y X X a T T' '' '' 2 Y''+Y = 0 +  = = − X X a T T' '' 2 X ''+X = 0 '( ) 0 2 T  +  a T = b m y Ym  = sin l n x X m  = sin ( ) exp[ ( ) ] 2 2 2 2 2 2 2 a t b m l n T t mn   = − +