Descartes' rule of signs - Polynomial Functions
Descartes' rule of signs
Lessons
Notes:
Descartes' Rule of Signs
For a polynomial :
the number of positive roots = the number of sign changes in , or less than the sign changes by a multiple of 2.
the number of negative roots = the number of sign changes in , or less than the sign changes by a multiple of 2.
Note: Before applying the Descartes' Rule of Signs, make sure to arrange the terms of the polynomial in descending order of exponents.
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Intro Lesson
Introduction to Descartes' Rule of Signs
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1.
Use Descartes' Rule of Signs to Determine the Number of Positive and Negative Roots
Use Descartes' Rule of Signs to determine the possible number of positive roots and negative roots: -
2.
Use the Rational Roots Theorem, together with Descartes' Rule of Signs, to Find Roots Effectively
Solve:
