I'm still unable to come up with a formula in terms of x1 and x2 However in the next problem I'm given values for the variables.

x1 = 30 x2 = 40

and the distance between x1 and x2 = 100.

So using what we know about right triangles, I found these values:

sorry, the drawing isn't to scale.

Using the arcsine function, I found that angle P is 21.801

and angle q is 16.999

(in degrees)

So, in solving for y

y CSC (16.99) + y CSC (21.801) = 100

Using algebra I get

y = 100/( CSC (16.99) + CSC (21.801))

Which comes out to about 16.2002 for the length of y

Does that seem right?

I apologize for how messy and incoherent that probably was.