This video is saying
in order to better visualize the cost function J, I'm going to ...
with the same structure, we could make this sentence
in order to better solve a problem
sounds uncommon, is something wrong?
English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.Sign up to join this community
“better” is being used as an adverb here. You can also do the same with “best”.
If X is a better (or the best) solution to problem Y, then you can say that “X better (or best) solves Y”.
Note that X is often implicitly compared to the status quo, such as “we can better serve our customers by staying open an hour later (than we do today).”
The specific structure “to [adverb] [verb]” is called a “split infinitive”, and some purists dislike it, but it is nevertheless commonly used and accepted. The canonical example is “to boldly go” from Star Trek.