tExpand() and tCollect()

The functions tExpand() and tCollect() are located in the Algebra menu in the Trig sub-menu. tExpand() will expand functions such as sin(2x) to 2sin(x)cos(x). Someone apparently didn't program half angles in apparently, because sin(x/2) will not expand. The opposite function, tCollect(), will take a function such as 2sin(x)cos(x), and give you back sin(2x).