The ignition formula generally refers to Wallis formula. Wallis formula is a formula about infinite product of pi, but there is only multiplication and division in Wallis formula, and even roots are not needed, so the form is very simple. Although Wallis formula has no direct influence on the approximate calculation of π, it plays an important role in the derivation of Stirling formula.

character introduction

Zhang Yu, a math teacher who set sail for the postgraduate entrance examination, has been engaged in advanced mathematics teaching and postgraduate counseling for many years, and has published many papers in national core journals, one of which was selected for the "2007 Global Sustainable Development Conference".

representative works

Zhang Yu gives 9 lectures on linear algebra, 9 lectures on mathematical probability theory and mathematical statistics for postgraduate entrance examination, and the classic 1000 questions on mathematical sources for postgraduate entrance examination.

Zhang Yu took the postgraduate entrance examination for a complete answer to the real math questions, and Zhang Yu took the postgraduate entrance examination for a closed-door math exercise 180 questions.

Eight Volume of Final Prophecy of Postgraduate Mathematics Proposer and the Last Four Volume of Postgraduate Mathematics by Zhang Yu.

Lecture notes on probability theory and mathematical statistics

Personal introduction

Academic background: Professor, the backbone teacher of the National Excellent Curriculum Construction of the Ministry of Education. He has published many papers in national core journals, one of which was selected for the 2007 Global Sustainable Development Conference, and delivered a keynote speech 15 minutes.

Counseling qualification: I have been engaged in advanced mathematics teaching and postgraduate counseling for many years, and I am a key expert in the national advanced mathematics question bank. Participated in the revision of graduate mathematics teaching syllabus and the composition of national mathematics examination for many times. Postgraduate entrance examination is a key expert in the study of real questions over the years.

Teaching method: Initiating the "subject-source teaching method", deeply analyzing the classic mistakes, and knowing the students' weaknesses in advanced mathematics like the palm of his hand, so that his postgraduate counseling is targeted, relevant and effective.