#
# Numerical Mathematics and Computing, Fifth Edition
# Ward Cheney & David Kincaid
# Brooks/Cole Publ. Co.
# (c) 2003
#
# file:  num_integ2
#
# Numerical approximation for the integral of
# the function f(x) = cos(2x)/exp(x) over the 
# interval [0, 2pi]:

 Digits := 20;
 int(cos(2*x)/exp(x), x = 0..2*Pi);
 evalf(%);