Answer :
Solution:
(a)
[tex]x^3-x^2+4x-6=0[/tex]Using Descartes rule of signs;
The first is positive to negative, then negative to positive and lastly positive to negative.
Thus;
It has one positive real root.

Solution:
(a)
[tex]x^3-x^2+4x-6=0[/tex]Using Descartes rule of signs;
The first is positive to negative, then negative to positive and lastly positive to negative.
Thus;
It has one positive real root.