Question

What are the possible number of positive, negative, and complex zeros of f(x) = –3x4 – 5x3 – x2 – 8x + 4 ?

Answer 1

Descartes' Rule of Signs tells you there could be two positive and two negative roots, but either of those pair of roots could be replaced by a pair of complex conjugates.

In actuality, that function has two positive and two complex roots.

Answer 2

3 sign changes in f(x) --> 1 or 3 positive zeros

1 sign change in f(-x) --> 1 negative zero

4 total zeros --> 0 or 2 imaginary zeros

Answer 3

thanks

Answer 4

:D ty!!