In the following functions, () is the original function of xcosx a:-xsinx-cosx b:-xsinx+cosx c:xsinx+cosx d:xsinx-cosx

In the following functions, () is the original function of xcosx a:-xsinx-cosx b:-xsinx+cosx c:xsinx+cosx d:xsinx-cosx

c:xsinx+cosx