Question

What is a “real” zero?

1. A solution to a polynomial.
2. A non-imaginary number.
3.An x-intercept of a polynomial.
4. All of the above.

The answer is 4, right?

Answer 1

This is a nutty question.

a "real" zero is a solution to a plynomial whch is equal to zero.

If poly(x)=0, then a real zero is a real (not complex) value of x which satisfies the equation.

So 1. would be a good answer, but it should say "a real solution that makes the polynomial value zero.

2. would be ok, but is should say "a number that does not contain an imaginary value"

3. might be right, but the x axis has to be a real number axis, and in graphing polynomials, there is no requirement it has to be plotted on a real number plane.

4. could be right.

So I guess I assume your teacher is just sloppy with language, and teaching you to do the same. Go with 4. But it is important to understand what I said on each answer.