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Why is square of any number not negative?
- Consider a positive number. Its square is a multiple of it and
itself, which is a positive number. positive multiplied by positive
is positive.
- Consider zero. Its square is zero multiplied by zero, which is
zero. As you know, zero is not a negative number
- Consider a negative number. Its square is a multiple of
it and itself, that is, it is a negative number multiplied by a
negative number. And, as you know, negative multiplied by negative
is positive.
Since all numbers out there are either negative, zero or positive,
we have proven that all squares are positive numbers.
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