Show that the boundary conditions X(b)=wX(a) +zX'(a)

[matpo39]

I need a little help getting started here,

Show that the boundary conditions X(b)=wX(a) +zX'(a)

and
X'(b) = yX(a) + dX'(a) on the interval a<=x<=b are symmetric if and only if wd-zy=1

i know that the a set of boundries are symmetric if f '(x)g(x) - f(x)g'(x) = 0 evaluated at x=a and x=b. but i am confused on what f(x) and g(x) would be.
if some one can help me get this problem started it would be greatly appreciated.

thanks

 

[Astronuc]

What would it mean for the BC to be 'symmetric'?

X(a) = X(b) and X'(a) = -X'(b) perhaps.