strive vs undertake

strive

verb
  • To try to achieve a result; to make strenuous effort; to try earnestly and persistently. 

  • To struggle in opposition; to be in contention or dispute; to contend; to contest. 

  • To vie; to compete as a rival. 

undertake

verb
  • To take upon oneself; to start, to embark on (a specific task etc.). 

  • To commit oneself (to an obligation, activity etc.). 

  • To pass a slower moving vehicle on the curbside rather than on the side closest to oncoming traffic. 

noun
  • The passing of slower traffic on the curbside rather than on the side closest to oncoming traffic. 

How often have the words strive and undertake occurred in a corpus of books? (source: Google Ngram Viewer )