Using the property of intersecting chords for the external point P, we have PA multiplied by PB equals PT squared, which is also equal to PO squared minus the radius squared. Since ON is perpendicular to the chord AB, applying the Pythagorean theorem to the right triangles formed gives PO squared as PN squared plus ON squared, and the radius squared as AN squared plus ON squared. Substituting these into the first equation results in PA multiplied by PB equaling PN squared plus ON squared minus AN squared minus ON squared, which simplifies to PN squared minus AN squared, proving the statement is true.