Question 472568: Use Descartes' Rule of Signs to determine the possible number of positive and negative real zeros of:
f(x)= x^5 - 3x^4 - 2x^3 + x^2 +5
Answer by robertb(5830)   (Show Source):
You can put this solution on YOUR website! Since there are 2 variations of signs, there are 0 or 2 positive real zeros.
If x is replaced by -x, the resulting polynomial is  , which has 1 variation of sign, hence exactly one negative zero. Hence, either there are
(i) 2 positive, 1 negative, and 2 complex zeros,
OR
(ii) 0 positive, 1 negative, and 4 complex zeros.
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