||'''Book'''|| Advanced Engineering Mathematics ||
 ||'''Author'''|| Erwin Kreyszig ||
 ||'''Edition'''|| 8th Edition ||

/* code_begins */

{{{
var ('z1, z2')
z1 = 4-6*i
z2 = 2+2.5*i
arg(z1*z2)
-0.086738338676
arg(z1)+arg(z2)
-0.086738338676

}}}

/* code_ends */

 * '''Solution by''': 
   * sampath reddy, student, VREC
   * sajith kumar, student, VNRVJIT