Warm-up Complete this as a group on you Board. You have 15 minutes And why?
Rational Root(zero) Theorem Objective: SWBAT find zeros of a polynomial by using Rational Root Theorem
Terminology: Solutions (or roots) of polynomial equations Zeros of polynomial functions “r is a zero of the function f if f(r) = 0” zeros of functions are the x values of the points where the graph of the function crosses the x-axis (x-intercepts where y = 0)
Rational Root Theorem: Suppose that a polynomial equation with integral coefficients has the root p/q , where p and q are relatively prime integers. Then p must be a factor of the constant term of the polynomial and q must be a factor of the coefficient of the highest degree term. (useful when solving higher degree polynomial equations)
Solve using the Rational Root Theorem: 4x2 + 3x – 1 = 0 (any rational root must have a numerator that is a factor of -1 and a denominator that is a factor of 4) factors of -1: ±1 factors of 4: ±1,2,4 possible rational roots: (now use synthetic division to find rational roots) (note: not all possible rational roots are zeros!)
Ex 3: Solve using the Rational Root Theorem:
Ex 4: Solve using the Rational Root Theorem: possible rational roots:
Ex 5: Solve using the Rational Root Theorem: possible rational roots: To find other roots can use synthetic division using other possible roots on these coefficients. (or factor and solve the quadratic equation)