Where are the three Cogs
TOMB RAIDER: all of them are at dino area
cog#1: ledge above small pool in a cave.
cog#2: temple, you need to dive in the water.
cog#3: after jumping the broken bridge.
place them on gears at upstream area.
(see 1 part video http://www.youtube.com/watch?v=zjVjdKyt3vw )
TOMB RAIDER ANNIVERSARY:
cog#1: starting area with wolves.
cog#2: temple, no need to dive in the water.
cog#3: upstream (TR1 cog placing area)
place them on gears above wolves area.
(see 1 part video http://www.youtube.com/watch?v=cmbsRNgcFhY)
you should be specific in your question to avoid misleading.