(a) Show that every polynomial of degree 3 has at least one x-intercept.
(b) Give an example of a polynomial of degree 4 without any x-intercepts.
(a) Since complex roots show up in pairs, not all 3 roots can be complex, so at least one of them must be real! Or: Go back to your solution of Exercise 5. Every case has at least one real root.
(b) Now it can happen that all roots are complex! The polynomials and are such examples.
S.O.S MATHematics home page
Do you need more help? Please post your question on our
S.O.S. Mathematics CyberBoard.
Tue Jun 24 09:52:49 MDT 1997
Copyright © 1999-2018 MathMedics, LLC. All rights reserved.
Math Medics, LLC. - P.O. Box 12395 - El Paso TX 79913 - USA
users online during the last hour