All Posts : MaplePrimes Commons General Technical Discussions

n=1..2, or n=1..N where N = 2

March 10 2006 by jherod 100
false

0


I do not understand why these parts give different results. Part 1. > restart; > u:=(t,x)->sum(a[n](t)*sin(n*Pi*x),n=1..2); > diff(u(t,x),t); > D[1](u)(t,x); THE OUTPUT OF THE LAST LINE IS WHAT A HUMAN WOULD GET. Part 2. > restart; > N:=2; > u:=(t,x)->sum(a[n](t)*sin(n*Pi*x),n=1..N); > diff(u(t,x),t); > D[1](u)(t,x); THE OUTPUT OF THE LAST LINE IS 0, curiously. Part 3. > restart; > N:=2; > u:=(t,x)->add(a[n](t)*sin(n*Pi*x),n=1..N); > diff(u(t,x),t); > D[1](u)(t,x); THE OUTPUT OF THE LAST LINE ECHOES THE REQUEST. > I prefer the output of Part 1, of course. I can tolerate the output of Part 3. But, the output of Part 2 seems wrong. What am I not understanding? Jim Herod >

Loading Comments

You must be logged into your MaplePrimes account in order to post a comment. If you don't have an account, you can create an account here.

     

Forgot Your Password? Create an Account