I don't exactly understand Descartes' rule of signs so if someone could please help me on the equation attached?

Question

anonymous · Answer

attachment

loser66 · Answer

anonymous · Answer

Yeah use loser66's link its really long to explain without examples

anonymous · Answer

So I solve for f(-x) to get 3x^4+5x^3+5x^2-5x+2, ending up with possibly 2 negative roots?

anonymous · Answer

i couldn't tell you you didn't show the original equation

anonymous · Answer

if you changed the signs on your odd exponents then yes

anonymous · Answer

I attached a file with the original equation

asnaseer · Answer

there is a very good video explanation of this method here: http://www.youtube.com/watch?v=1utFwnmBOyU