Can you connect a bass amp to a power amp ?

I was just curious if this is possible?

What do you mean by "bass amp"? If you mean bass guitar you can connect it to a power amp if the bass amp has preamp, or low level, outputs. You may have to find the cables with the correct plugs on the end.

Mr Peabody is right that it can be done and I have seen it done myself mostly for higher end practice rigs for driving smaller bass cabinets but there is a bit of a difference in the connections and these connections impedance that must be addressed before things will work perfectly.