Good. Now consider the following matrix: 
where Nmin and Wmin are the North and West minute portions of the posted coordinates.
The cache is located at N45 xx.xxx W75 yy.yyy where xx.xxx and yy.yyy are the eigenvalues of this matrix. It should be obvious which is which.
You can check your answer here.
This puzzle is for the GAG19 event. Do not attempt to find the cache or log a find before 18:00 May 3, 2013. You will be plagued forever with singularities if you do.
Good Luck!