matrix simply tells you how to data points vary with each other and in fact they don't look at the covariance matrix but they look at the correlation matrix which is simply the scaled covariance matrix so one entry in this covariance matrix so you have n data points and this gives you a matrix that's n by n and that particular entry here like the entry IJ would simply state how does the angle of data point I correlate with the angle of data point J okay that's the that's the covariance matrix and now the hypothesis is if all