I'm looking for the E[XY] of the joint moment generating function of a couple of random variables (X,Y). We don't know if the variables are independent. I don't know how to solve the partial derivative ∂² E[e^(sX+tY)] ∂s ∂t
Joint moment generating function of (X,Y)
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probability-distributions
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0What information *do* you have about the variables? – 2017-02-03
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0I don't have any information, I think I need to find a general equation for the (X,Y) couple – 2017-02-03
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0Do we at least know if continuous of discrete they are? – 2017-02-03
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0I suppose they are continuous – 2017-02-03