# Thread: some clarification in normal distribution

1. ## some clarification in normal distribution

Hi,

I just have a doubt. What is "u" in the given link and is ther eany way to calculate u which is based on X(meu x, sigma x) and Y(meu y, sigma y)

Normal Difference Distribution -- from Wolfram MathWorld

thanks

2. For U= X-Y, then U is $\displaystyle N(\mu_X-\mu_Y,\sigma_X^2+\sigma_Y^2)$