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but what happens when we"ve gained a $x$-hatchet or a $y-$hatchet top top its own?

e.g. Say we desire $\operatornameVar

then us have $(x+y+1)^2=x^2+2xy+2x+y^2+2y+1$, so:$$\operatornameVar

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edited may 21 "14 in ~ 16:12

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request may 21 "14 at 16:09

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girlfriend almost acquired it other than the $$\textCov(aX, bY+c) = \textCov(aX, bY)+\textCov(aX,c) = Abdominal \textCov(X,Y) +0$$Since covariance of a arbitrarily variable through a consistent ins $0$.

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answered might 21 "14 in ~ 16:17

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If all friend desire ins the variance, getting it via the covariance recipe the means you"re doinns ins a lons even more complex 보다 it needs come be. Friend simply observe: $$\rm Var

**Then**girlfriend have the right to usage the covariance formula.

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answered might 21 "14 at 16:25

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