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1-Visitor
February 27, 2015
Solved

Derivative a scalar

  • February 27, 2015
  • 1 reply
  • 4812 views

Hello.

I'm trying to derive a formula which is a function of six values. Four of them are just constants but the other two are vectors of three values.

d = constant

L = constant

T = [T1, T2, T3]

T_inf = constant

E = [E1, E2, E3]

R = constant

I want to get three values from the dT_i. Thanks..

primehelp.png

Best answer by RichardJ

You can't take the derivative w.r.t a subscripted variable, or a variable that is a vector. The easiest solution is to first create a function, and then apply that to the vector variable.

1 reply

19-Tanzanite
February 27, 2015

It's hard to debug a picture. Try using the vectorize operator over the derivative of the function. If that doesn't work, please post the worksheet.

1-Visitor
February 27, 2015

Hello Richard.

Thanks for your reply. I couldn't figure this out so here is the file.

I hope someone can help.

BTW. I'm sorry for posting in wrong section. Though I was located in the "Calculus & Derivatives" when posted.

RichardJ19-TanzaniteAnswer
19-Tanzanite
March 2, 2015

You can't take the derivative w.r.t a subscripted variable, or a variable that is a vector. The easiest solution is to first create a function, and then apply that to the vector variable.