Conference rusure::math

1824.0. "int(exp(abs(t)),t=-infinity..infinity) in maple?" by STAR::ABBASI (only 5 days left..) Thu Dec 09 1993 00:41

    
    hi,
    
    
    i have this expression with absolute values all over it,
    but maple is giving me hard time with abs values, to explain
    as an example:
    
                              2 |t|
    if i want to integreate  e       from say -oo to oo
    
    i type 
    
    int(exp(2* abs(t)),t=-infinity..infinity);
    
    maple can't do it. 
    
    i use signum, but still it wont do it:
    
    int(exp(2* signum(t) * t ,t=-infinity..infinity);
    
    
    any one knows how to do this integral in maple?  once i know
    how i can apply the method to other things with abs in them.
    
    thanks,
    \nasser

How about
int(exp(2* (-t)),t=-infinity..0) + int(exp(2* t),t=0..infinity);

(Are you sure you didn't mean -abs(t)?)

    There is a reason that functions which contain abs are called
    "non-analytic".  Evaluate seperately the formula for regions where the
    sign of the expression in the abs is positive, and where it is negative
    with an appropriate "-" thrown in.  Sum the results of those regions.
    (in this case, the result is infinite)


				    Topher

    .1, .2
    
    thanks, i know i can break it out "manully", but sometimes(?) iam lazy and
    was hoping maple can do it for me as is so i will type in less  ;)
           
    \nasser