Messages

16

MAT244--Lectures & Home Assignments / question about the acid water problem

« on: September 21, 2018, 08:46:35 PM »

Can anyone explain how the equitation is built in the acid water problem in Lec0201? Also, Is the problems shown in class available to us?

17

MAT244--Lectures & Home Assignments / Re: substitution in integral

« on: September 12, 2018, 11:38:24 PM »

After reading it, I have a follow-up question. What's the difference between  w’(t)dt,  dw,  dw/dt,  dw(t)/dt?

18

MAT244--Lectures & Home Assignments / Re: substitution in integral

« on: September 11, 2018, 03:13:09 PM »

dt cannot exist and appear alone. How can we multiply dt on both sides since dt is not a number?

19

MAT244--Lectures & Home Assignments / Substitution in integral

« on: September 10, 2018, 09:49:24 PM »

dt means with respect to t.

dw means with respect to w.

w’(t)dt means take derivative to w with respect to t.

How can we substitute w’(t)dt with dw?

dw is a prepositional phrase but w’(t)dt is a complete action.