Question

What are the possible number of positive, negative, and complex zeros of f(x) = 2x3 – 5x2 – 6x + 4 ?

Answer 1

This Descartes Rule of Signs

2 sign changes so 2 or 0 positive roots

Then put -x and see there is 1 sign change so 1 negative root

So there is 1 negative and either 2 positive or 2 complex roots.