I have completed the first 2 courses in the specilization, and this is the 3rd and the last course in the specilization. Everything was very easy until the last week of the last course. But when the hard part comes, the lecturer does not give proofs/explanation in detail, and the questions remain unanswered in the forum for months. Generally speaking, if you know the subject before the course, you will learn nothing; if you do not know the subject before taking the course, you won't understand it by taking the course etiher unless you do research yourself; you will remember the conclusion but not how to derive it, which I believe is undesirable in a MATHEMATICS course. Not recommend to devote either your time or money to it.