What do you mean by approximation algorithm

Often, in a lot of texts concerning approximation algorithms i see the following notation (for example, here in page 19 of the pdf or the first page of the introduction):The content of the course will be as follows:Call merge (ar, l, m, r) 3.Close in value or amount but not precise.Know the definition for approximation algorithm?By the theorem above, that polynomial is optimal.

Ε> 0} for a problem p.A complete analysis of the running time of an algorithm involves the following steps:An algorithm a for problem p that runs in polynomial time.Determine the time required for each basic operation.Simple examples of approximation algorithms.Function approximation is a technique for estimating an unknown underlying function using historical or available observations from the domain.