CaptainRescue:"It mustave been pretty damn cold for that." Aroura borealus(northern lights) are not caused by low temps. they are caused by electro magnetic discharges sent out by the sun htat then enter the earths atmosphere and refract light from the sun that is over the earths termanater(place where light meets dark) fyi
the awnser is 0. the vector of ordinates for the input data=the vector of values at which to differentiate. for some J, XX(J) does not lie inside the interval[ X(1), X(N) ]
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