# Maximum Likelihood estimate

I am trying to distinguish between two letters (A and C) using the difference of sums of black pixels in their left and right half of the image. I assume they normal distribution of the class probability density functions p(x|k), where k={A, C}. I have to find mean and sigma (normal distribution is defined by them) using MLE. I have training data for estimations and test data to verify my estimates.

I know hot to use MLE to estimate only one parametre, but how to estimate both at once? Lets assume I know the a priori probabilities of P(A) and P(C).

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