$\"\"$

$\"x$ are factors of the polynomial function.

The polynomial function as a product.

$\"f$

$\"equal$ (Product of two same signs is positive)

$\"equal$ (Formula: $\"open$ )

Using FOIL method.

$\"equal$

$\"equal$ $\"\"$

$\"f$ is a polynomial function of least degree with integral coefficients and zeros of $\"\"$ .