||'''Book'''|| Calculus of One Variable ||
 ||'''Author'''|| Keith E. Hirst ||
 ||'''Edition'''||  ||

/* code_begins */

{{{
var('x n')
print "gamma(n) =",integrate(x**n*e**x,x,0,1)
}}}

/* code_ends */

 * '''Solution by''': 
   * Sabareesh Nikhil C,Student, IIT Bombay
   * Chandrahas Kolla, Student, IIT Madras