Sorry, Shades...I made this a little more complicated than I should have.....c is the focal distance = sqrt(5) = sqrt [ a^2 + b^2] = sqrt [1^2 + 2^2] = sqrt [1 + 4 ] = c
So, sqrt [c^2 - b^2] is just = a ......which, in this case = 1
So...I should have simplified the location of the vertices as
[ h + a , k ] and [ h - a, k] where h = 1/3 and k = 3 and a = 1
So....we get he same result as I gave originally
The vertices are located at
[1/3 + 1 , 3 ] and [ 1/3 - 1, 3] which simpliy to
[4/3 , 3 ] and [ -2/3, 3 ] as before
Sorry for the "overkill"
