I was messing about with a dot product, trying to simplify an expression, when I came across this equality by graphing. Why would these expressions be equal?
I noticed that:
But the $\cos(2x)$ in there really makes it tough. Also, somehow the $h$ factors out completely? Very strange! Hope somebody can figure it out!
Edit: Oops! I happened to only be looking at the function for situations where r >> h. When this isn't true, the equations becomes obviously different. The square rooted equation seemed so close to simplifying though :(