Jacob Bernoulli (? , 1654- 1705), one of the representatives of Bernoulli family, is a Swiss mathematician. It is recognized as one of the pioneers of probability theory. He was the first person to use the term "integral" and one of the first mathematicians to use the polar coordinate system. As explained earlier, with the increase of test times, the frequency is stable near the probability. He also studied catenary and determined the isochronous curve equation. He also proposed Bernoulli test and theorem of large numbers in probability theory.