Updated 29 July 2019

In addition to the many welcome donations that help me keep the site going financially, readers have made many kind comments. Here are a few of them, by topic.

## Trigonometry

### I am feeling empowered

“I have been working through some trig problems by deriving the formulas as you suggest at Proof of Euler’s Formula and I am feeling empowered. While I may end up memorizing some of them as I go along, it's nice to know where they come from and no longer either fear forgetting them or have to try to remember those awful mnemonics, which I find as hard to remember, interpret, and apply as doing the derivations, and much less enlightening. … I am also now looking forward to seeing what else can be done with Euler's formula and how it can be derived.”

### Is it really Trig without Tears though?

“I think you may have to discard the name of your textbook, Trig without tears. I am a 4th-year engineering student who has always had a poor foundation in trigonometry, but after doing very poorly because of it on my last exam, I decided to put an end to that. I spent the last few days going over your Trig without tears textbook, and I find myself almost brought to tears because this subject, which has eluded my understanding for so many years and held me back, is finally under my command. I actually found myself using the derivations you taught in my circuit analysis homework problems, without even thinking about it. I have sent you a small … donation, but I feel that does not begin to equate to the value your work has given me. I hope this email can help in some small way to bridge that gap.

“Thank you so very very much.”

## TI-83/84 Procedures

### Saved me for circuit analysis!

“Your article on rectangular and polar notation just saved me for my AC Circuit Analysis class!!”

### Thanks!

“Thank you so much for creating Math200I [now MATH200A Program — Basic Statistics Utilities for TI-83/84 and MATH200B Program — Extra Statistics Utilities for TI-83/84Editor] for the TI-83. I am taking a very daunting Statistics final on Tuesday at San Diego Mesa College, and have been searching for good Statistics programs for my classic TI-83. Looking at your release notes, I guess I was lucky that I found the program when I did - you just released the TI-83 version!

“I downloaded it for the critical-t function, but it seems that it will be able to handle many more functions than that.

“Thanks again. I really appreciate it. ”

## Statistics

### Your book put my mind at ease

“I am struggling in my statistics class. Just reading the first chapter of your book has put my mind at ease. Much easier reading than the school textbook. … Thank you for speaking plain English in the book!”

### Acing the final

“I'm pretty sure that this will make the difference between me acing and failing my Statistics final. I wish I'd found this months ago!”

### First time teaching

“I found your website most helpful. This is the first time I have taught Multivariate Statistics and found myself with a class of doctoral students who ranged from those who used stats in their work to those who could not remember the difference between a median and a mode. And I am no whiz kid with statistics. I appreciate your style of presentation and referred my students to your website. Continue on in your endeavors—you are doing good work.”

### Changed my perspective of statistics

“This textbook has changed my perspective of statistics and has opened a new world of math for me. This beats any stats textbook out there. I'm enrolled in AP Stats at my school and as the course is tedious it is also tremendously beneficial and this book will surely help me achieve a 5 on the exam in May. Thank you for helping out the millions of students that have read/will read this book.”

### One of the best treatments available

“I would like to thank you for the excellent resource. … In particular the stats modules are lucid and accessible.

“In my experience, (I am re-tooling for a new position in finance), this is one of the best treatments available.

“Your students are very fortunate to have this and I hope they appreciate the work & thought that has gone into this course.”

### Appreciation

“Dear Mr. Stan,

“I really thank you very much for explaining the statistics in a very very easy way that novices like me are able to understand such a complex subject in at a glance. I really appreciate your effort on teaching the statistics in such a easy way. Please keep it up.

“Many thanks.”

## What’s New

28–29 July 2019: Added Your book put my mind at ease and I am feeling empowered.

4 July 2018: New document.

Because this site helps you,