# User talk:HANHONG

## Contents

Question 05 (a) in MATH110(2017)218:43, 27 February 2018
Question 05 (b) in MATH110(2017)007:17, 27 February 2018
MATH 152 April 2015 Q29123:38, 13 February 2018
end points123:33, 8 February 2018

## Question 05 (a) in MATH110(2017)

Hi Han,

Thanks for writing solution for MATH110(2017)!

In Question 05 (a), at the first line (although we can justify it with product rule), I believe what you actually used is the chain rule. Also, can you explain very slowly how you use the chain rule? (for example what is g and h in f(x) = g(h(x)) and then find g' and h', then using the formula you got the derivative). As I mentioned, some students in this class really have difficulty even this part.

Then, for us finding critical points are obvious, but some students don't know how to factor out (4-x^2). So please mention that part too. Otherwise, it could be really hard for them to see that ${\textstyle f'>0}$ when ${\textstyle x<-2}$......

Thanks, Hyunju

07:12, 27 February 2018

Hi Hyunju,

You are right, I meant chain rule and I will add details about finding zeros.

Best,

Han

17:14, 27 February 2018

Thank you so much, Han!

18:43, 27 February 2018

## Question 05 (b) in MATH110(2017)

Hi Han,

Can you explain how you get the zeros?

Thanks!

Best, Hyunju

07:17, 27 February 2018

## MATH 152 April 2015 Q29

Hi Han,

Thanks for your work so far! You made several errors in your solution to this question, which I have corrected. (In particular, note that matrix multiplication is not commutative.) Please check the history to make sure that you understand where you went wrong, and change the flags to QGH and QGS once you have done so.

Best,

22:49, 13 February 2018

Hi Nicholas,

Thank you for correcting, I don't remember what I did, I guess I probably multiply it from right.

Best,

23:38, 13 February 2018

## end points

Hi Han,

Thank you for your great work on MATH 101! But please don't forget to change the flags from CH, CS to RH, RS. I changed for all questions you've wrote hints and solutions, so you don't need to do that for them.

For the solution Math Exam Resources/Courses/MATH101/April 2017/Question 06 (b)/Solution 1, I think you need to check the convergence for the end points too. i.e, when |x-1| = 1/3. Because the ratio test doesn't give the information on this. If you agree, can you revise the solution?

Thanks!

23:10, 8 February 2018

Hi Hyunju,

First, thank you for changing flags, I didn't even realize it. I won't forget it next time.

Second, I think you are right about the end points, Although It doesn't affect the result here, it's really important to include them. I will correct right away so you can check. Thank you! Best

Han

23:33, 8 February 2018