SOLUTION: Use the Rational Root Theorem to find all the zeros and write a linear factorization of:𝑓(𝑥) = 𝑥^3 − 𝑥^2 + 𝑥 − 21
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-> SOLUTION: Use the Rational Root Theorem to find all the zeros and write a linear factorization of:𝑓(𝑥) = 𝑥^3 − 𝑥^2 + 𝑥 − 21
Thank you!
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Question 1125326: Use the Rational Root Theorem to find all the zeros and write a linear factorization of:𝑓(𝑥) = 𝑥^3 − 𝑥^2 + 𝑥 − 21
Thank you! Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! factors of the constant 21 are +/-21/1 and +/-3/7. Factors of the leading coefficient are +/-1
try 1 and -1
1-- -1-- 1-- - 21
1-- 0---1----20
need larger numbers so try -3
1-- -1-- 1-- -21
1-- -4-- 13-- -60 now plus 3
1-- 2-- 7-- 21. That works
(x-3) is a factor.
the other factor is (x^2+2x+7), where the discriminant is -45, so that has complex roots only.
