Maybe this will settle the "argument"
Dr. Math says -4: http://mathforum.org/library/drmath/view/53194.html

As does Wikipedia: http://en.wikipedia.org/wiki/Order_of_operations

>The whole point is that when there are no parenthesis, you must still follow the order of operations. Given no parenthesis, in
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>-2^2
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>the exponentiation goes first and then the unary.
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>Also, -2 can indeed be expressed as 0-2, but there were no parenthesis in the original function posed and there should have been to be explicit. You can not arbitrarily add parenthesis to one and not the other when no parenthesis existed.
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>So, I still disagree :o)