 
 
 
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.
 
Input :
sturmab(x^2*(x^3+2),x,-2,0)
Output :
1
Input :
sturmab(x^3-1,x,-2-i,5+3i)
Output :
3
Input :
sturmab(x^3-1,x,-i,5+3i)
Output :
1
Warning !!!!
 P is defined by its symbolic expression.
Input :
sturmab([1,0,0,2,0,0],x,-2,0),
Output :
Bad argument type.
 
 
