Question

Find the possible number of positive real roots of f(x) = -2x3 + 11x2 - 3x + 4

Select one:
a. 3 or 1 positive real roots
b. 1 or 0 positive real roots
c. 2 or 0 positive real roots
d. 3, 2, 1 or 0 positive real roots
Is this B?

Answer 1

@phi

Answer 2

@whpalmer4

Answer 3

none!

Answer 4

really?

Answer 5

use Descartes rule of signs
http://www.purplemath.com/modules/drofsign.htm

Answer 6

I count 3 sign changes.