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Hi

I have to say true or false, and then demonstrate my answer

"if taking any 3 Real numbers (a, b, c), we have at least 2 of the same sign"

For me its true, i was thinking of creating a triplet (x, y, z), where

x=1 if "a" positive, x=0 if "a" negative, same for y, and z

and show that with the all the (x, y, z) possibilities, you had always 2 of the same sign

But then, i realized, what if one of the reals a, b, c is equal to 0 ?

like if (a, b, c) = (0, 0, 0)

Is zero considered positive or negative, or both ?

If so, i would have to add another value to the reals of the (x, y, z) triplet , 2, which i can then take as positive when i need or as negative when i need

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# Homework Help: Maybe stupid question - zero positive or negative ?

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