on the 2-2 point doesn't give life. After the connection at , White still has only one eye in the corner. Black can also play atari with at .
Connecting at is the third way to save the two stones. Black plays hane at and makes a placement at - and White is dead, because now a and b are miai. Black could also kill by playing on the vital point of this shape, namely .
ProtoDeuteric: Does this work?
unkx80: should play at for life, and should play at to kill with a bulky five.
go student: What about this. There should be at least a ko, as I can see. Please tell me if I miss something
atari at a or connect at below are clean kills