One fellow mentions,
I haven't been able to pin down what it mean to 鋭く生きる, 牙のように or not. My first thought was that it was something like "living on the edge," or "living dangerously". This seems to be reinforced by the fact that the thread creator replies with a "格好いい（笑）". A different search result (http://plaza.rakuten.co.jp/jirojirojirodan/diary/200610160000/), however, seems to suggest just the opposite:
That suggests to me that in order to live more 鋭く, the blogger is studying economics in order to better maintain her household finances. It sounds here like 鋭く生きる is referring to responsible living.
Could it have multiple meanings depending on what it's referring to, or am I just interpreting it incorrectly? Help please!