>>827
手間やなー
f=sin2x/{(cosx)^2+(sinhy)^2}
f{(cosx)^2+(sinhy)^2}=sin2x

fx{(cosx)^2+(sinhy)^2}-f*sin2x=2cos2x
fxx{(cosx)^2+(sinhy)^2}-2fx*sin2x-2f*cos2x=-4sin2x


fy{(cosx)^2+(sinhy)^2}+f*sinh2y=0
fyy{(cosx)^2+(sinhy)^2}+2fy*sinh2y+2f*cosh2y=0

(fxx+fyy){(cosx)^2+(sinhy)^2}=2fx*sin2x+2f*cos2x-4sin2x-2fy*sinh2y-2f*cosh2y

で挫折・・