I seem to have got some questions hopefully though

1)Let roots be

3)If one root is zero,then let .

Now if has real roots then will have roots(By Rolle's theorem) and consequently will have roots for which the condition is that the equation

must have its discriminant greater than zero.

i.e.

4)Since all the coefficients are positive then by Descartes rule of signs the equation will have atmost zero positive roots.Therefore all the roots of the equation are negative.

It is the 2) that I am not getting