First Derivative

[Guest]

I wish to know, how do we find out "First Derivative" in MS Excel?
Well there is any inbuilt function is available for MS Excel??
if any please let me know

 

[Harlan Grove]

I wish to know, how do we find out "First Derivative" in MS Excel?
Well there is any inbuilt function is available for MS Excel??
if any please let me know

No, there's no general derivative function.

If you had a polynomial with coefficents in a range named COEF, and
the polynomial were evaluatedd as (x<>0)

=SUMPRODUCT(COEF,x^(ROWS(COEF)-MIN(ROW(COEF))))

you could calculate the derivative at x using

=SUMPRODUCT(COEF,(ROWS(COEF)-MIN(ROW(COEF)),
x^(ROWS(COEF)-MIN(ROW(COEF))-1))

If you had a table of x and f(x) values (in X and Y columns,
respectively) with the x values uniformly graduated, you could
calculate the numerical derivative for, say, X99 using the formula

=(Y97-Y101-8*(Y98-Y100))/12/(X99-X98)

 

[Guest]

Hi harlan!

Thank you for the post, i have x and f (x) data, i will try for numerical
differenciation. Thank you very much.

chetan

 

[Bernard Liengme]

Why not use LINEST to find the polynomial of best fit ( see
http://people.stfx.ca/bliengme/ExcelTips/Polynomial.htm) then follow
Harlan's idea.
best wishes

 

[Guest]

Thank you Bernard!
I will encorporate your words of wisdom to my calculations
tabk you both again

chetan