Note: These formulas have been transcribed from EPSG Guidance Note #7-2. Users are encouraged to use that document rather than the text which follows as reference because limitations in the transcription will be avoided.¶¶To derive the projected Easting and Northing coordinates of a point with geographical coordinates (lat,lon) the formulas for the one standard parallel case are:¶¶E = FE + r sin(theta)¶N = FN + r0 - r cos(theta)¶where¶n = sin lat0¶r = a F t^n k0     for r0, and r¶m = cos(lat)/(1 - e^2 sin^2(lat))^0.5     for m0, lat0, and m2, lat2 where lat1 and lat2 are the latitudes of the standard parallels.¶t  = tan(pi/4 - lat/2)/[(1 - e sin(lat))/(1 + e sin(lat))]^(e/2)   for t0 and t using lat0 and lat respectively.¶F = m0/(n  t1^n)¶theta = n(lon - lon0)¶¶The reverse formulas to derive the latitude and longitude of a point from its Easting and Northing values are:¶¶lat = pi/2 - 2arctan{t'[(1 - esin(lat))/(1 + esin(lat))]^(e/2)}¶lon = theta'/n +lon0¶where¶theta' = arctan[(E - FE)/{r0 -(N - FN)}]¶r' = +/-[(E - FE)^2 + {r0 - (N - FN)}^2]^0.5  taking the sign of n¶t' = (r'/(a k0 F))^(1/n)¶and n, F, and rF are derived as for the forward calculation.