<span>A rational number can be written in the form:
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The number isn't equal to zero because the division by zero is not defined. So we can represent rational numbers by a repeating or terminating decimal, for instance in the following four exercises we have:
A quadratic function has a degree of 2 so there will be two roots. The statement says the function does NOT CROSS THE X-AXIS so there are no real roots. That means both roots must be imaginary (complex).