Every mathematical function has a range and a domain. The range of a function is the set of possible outputs the function has. In this case, we know that our output (y) must be a positive number because if we take any real number (x) and square it, the result will be positive (negative x negative = positive).So we know that the range will not include any negative values. However, we can include 0 in the range as 0 x 0 = 0. Therefore, our range will be 0 to infinity (as x is any real number).