Question

help
Use Descartes' Rule of Signs to find the number of possible positive real roots and the number of possible negative real roots for the function f(x) = x4 + 2x3 - 3x2 - 8x - 4.






a.


positive 1; negative 3 or 1


c.


positive 3; negative 3 or 1




b.


positive 1; negative 3 or 5


d.


positive 3; negative 3 or 5