go at vs set to

go at

verb
  • To try to solve a problem a specific way; to undertake a task. 

  • Used other than figuratively or idiomatically: see go, at. 

  • To initiate an attack on or an argument with. 

set to

verb
  • To begin something with determination; to commence a long and difficult task or project. 

How often have the words go at and set to occurred in a corpus of books? (source: Google Ngram Viewer )