Maxima Function
residue (expr, z, z_0)
Computes the residue in the complex plane of
the expression expr when the variable z assumes the value z_0. The
residue is the coefficient of (z - z_0)^(-1)
in the Laurent series
for expr.
(%i1) residue (s/(s**2+a**2), s, a*%i); 1 (%o1) - 2 (%i2) residue (sin(a*x)/x**4, x, 0); 3 a (%o2) - -- 6