Question

According to Descartes Rule, how many positive real roots would the polynomial 5x^4 + 3x^3 - 7x^2 + x - 3 have?



3 or 1 positive real roots
3 positive real roots
5 positive real roots
3 and 5 positive real roots

Answer 1

I think its 3 positive real roots.but not sure.

Answer 2

There are three sign variations so 3 or 1 positive roots.

Answer 3

(x)= ++-+- 3 or 1 roots
(-x)= +---- 1 root