The Rational Root Theorem is a useful technique for identifying potential rational roots of a polynomial equation.
According to the Rational Root Theorem, if a polynomial equation with integer coefficients has a rational root, that root can be expressed in the form qp, where p is a factor of the constant term and q is a factor of the leading coefficient. This implies that to determine the possible rational roots of a polynomial, we should first list all the factors of the constant term and all the factors of the leading coefficient. We can then create all possible fractions by combining one factor from each list.
For instance, consider the polynomial equation
2x3+5x2−3x−2=0.Here, the constant term is −2, which has factors of ±1 and ±2. The leading coefficient is 2, which also has factors of ±1 and ±2. Consequently, the potential rational roots of this equation are formed by the combinations of these factors:
±11,±21,±12, and ±22.These fractions simplify to the possible roots: ±1, ±21, ±2, and ±1.
To utilize the Rational Root Theorem for solving a polynomial equation, we can test each of the identified potential rational roots by substituting them into the equation to see if the result equals zero. If we discover a root that satisfies this condition, we can apply polynomial division to factor the equation and uncover the remaining roots. If none of the potential rational roots yield a solution, we may need to employ alternative methods, such as the quadratic formula or numerical techniques, to find the roots.
![]() 100% | ![]() Global | ![]() 97% | |
---|---|---|---|
Professional Tutors | International Tuition | Independent School Entrance Success | |
All of our elite tutors are full-time professionals, with at least five years of tuition experience and over 5000 accrued teaching hours in their subject. | Based in Cambridge, with operations spanning the globe, we can provide our services to support your family anywhere. | Our families consistently gain offers from at least one of their target schools, including Eton, Harrow, Wellington and Wycombe Abbey. |
![]() 100% |
---|
Professional Tutors |
All of our elite tutors are full-time professionals, with at least five years of tuition experience and over 5000 accrued teaching hours in their subject. |
![]() Global |
International Tuition |
Based in Cambridge, with operations spanning the globe, we can provide our services to support your family anywhere. |
![]() 97% |
Independent School Entrance Success |
Our families consistently gain offers from at least one of their target schools, including Eton, Harrow, Wellington and Wycombe Abbey. |
At the Beyond Tutors we recognise that no two students are the same.
That’s why we’ve transcended the traditional online tutoring model of cookie-cutter solutions to intricate educational problems. Instead, we devise a bespoke tutoring plan for each individual student, to support you on your path to academic success.
To help us understand your unique educational needs, we provide a free 30-minute consultation with one of our founding partners, so we can devise the tutoring plan that’s right for you.
To ensure we can best prepare for this consultation, we ask you to fill out the short form below.