Zhang Yu's six important inequalities: triangle inequality; Geometric average; Inequality between arithmetic mean and root mean square; Young's inequality; Cauchy inequality; Schwartz inequality; Holder inequality. Basic inequality is an inequality that is mainly used to find the maximum value of some functions and prove it.

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".

Zhang Yu, Ph.D., is the author of Lecture on Advanced Mathematics for Postgraduate Entrance Examination 18 and Classic on the Origin of Mathematics for Postgraduate Entrance Examination 1000.

Representative works:

Advanced Mathematics for Postgraduate Entrance Examination 18 Lecture.

Lecture 9 on Zhang Yu's linear algebra.

9 lectures on mathematical probability theory and mathematical statistics for postgraduate entrance examination.

One's deceased father grind mathematics problem source classic 1000 problem.

Zhang Yu took part in the postgraduate entrance examination for mathematics.

One hundred and eighty questions about Zhang Yu's cultivation of postgraduate mathematics behind closed doors.

Postgraduate entrance examination mathematics proposer ultimate prediction eight volumes.

The last four volumes of Zhang Yu's postgraduate mathematics.

Lecture notes on probability theory and mathematical statistics.