Difference between v5.2 and v7 and inability of v7 with trigonometric functions

*To*: mathgroup at smc.vnet.net*Subject*: [mg119372] Difference between v5.2 and v7 and inability of v7 with trigonometric functions*From*: Rolf Schramek <subirolf at googlemail.com>*Date*: Wed, 1 Jun 2011 04:32:21 -0400 (EDT)

Can someone explain me the following behaviour of v7. If there is a reason I might accept it. v5.2: (=CE=BB = =CF=80; 2/=CE=BB Integrate[y0[x] Sin[n k x], {x, 0, =CE=BB}, Assumptions -> n =E2= =88=88 Integers] Output: 8 Sin[n =CF=80 /2] / (3 n^2 =CF=80^2) v7: (=CE=BB = =CF=80; 2/=CE=BB Integrate[y0[x] Sin[n k x], {x, 0, =CE=BB}, Assumptions -> n =E2= =88=88 Integers] Output: (2 ( 4 Sin[n =CF=80 /2] - Sin[2 n =CF=80] ) / (3 n^2 =CF=80^2) Further Simplify gives same result as v5.2: Simplify[%, , Assumptions -> n =E2=88=88 Integers] But v7 seemes to be weaker and much slower with those terms. ?? Thank you