用matlab的dsolve命令求解失败，结果如下：>>syms f;a=dsolve('Dx=(sqrt((f-x)^2+y^2)-f+x)/y')Warning: Explicit solution could not be found. > In dsolve at 120 a = [ empty sym ]我把f用数值代替，比如1，结果如下：>> a=dsolve('Dx=(sqrt((1-x)^2+y^2)-1+x)/y')Warning: Explicit solution could not be found. > In dsolve at 120 a = [ empty sym ]warning的意思...
