List Possible Rational Roots: List the possible rational roots of the polynomial x4+x2+1 using the Rational Root Theorem.
Rational Root Theorem Not Applicable: The Rational Root Theorem is not applicable here because the polynomial x4+x2+1 has no term with x3 or x, and it is not a polynomial of the form axn+bx+c. We need to look for other methods to factor this polynomial.
Recognize Quadratic Form: Recognize that x4+x2+1 is a quadratic in form with respect to x2. Let y=x2, then the polynomial becomes y2+y+1.
Factor Quadratic Using Formula: Attempt to factor the quadratic y2+y+1 using the quadratic formula to find its roots.
Calculate Discriminant: The quadratic formula is y=2a−b±b2−4ac, where a=1, b=1, and c=1 for the quadratic y2+y+1.
No Real Roots: Calculate the discriminant Δ=b2−4ac=12−4(1)(1)=1−4=−3.
Polynomial Cannot Be Factored: Since the discriminant Δ is negative, there are no real roots for the quadratic y2+y+1, and thus it cannot be factored over the real numbers.
Polynomial Cannot Be Factored: Since the discriminant Δ is negative, there are no real roots for the quadratic y2+y+1, and thus it cannot be factored over the real numbers.Since the polynomial x4+x2+1 cannot be factored over the real numbers, we can say that one of its factors is itself, x4+x2+1.