Question

in descartes' rule of signs, say the equations is x^4-x^2+4. If we are looking for how many times the sign changes would x^4 to 0x^3 count as a sign change?

Answer 1

i believe teh zero coeff is simply ignored; its a term by term count

Answer 2

x^4 -x^2 +4 simply has 2 changes