5.28.16 Number of zeros in [a,b) : sturmab
sturmab takes four arguments: a polynomial expression P, a
variable name and two real or complex numbers a and b
if a and b are reals,
sturmab returns the number of sign changes of P on (a, b].
In other words, it returns the number of zeros in [a,b) of the
polynomial P/G where G=gcd(P,diff(P)).
- if a or b are complex,
sturmab returns the number of complex roots of P in the rectangle
having a and b as opposite vertices.
P is defined by its symbolic expression.
Bad argument type.