Talk:Partial derivative

Is this accurate? --Remi 22:08, 26 May 2008 (UTC)

copy material from deleted mispelled version.

Partial derivatives are when the rates of change of a cross-sectional function gives only part of the picture. Instead of the derivative having a notation of dR/dr the partial derivative notation is ∂R/∂r. This notation is to remind ourselves that there is more than one input variable in the underlying function R.

How to find ∂R/∂r, you will have to treat r as a variable and c as a constant. Make note that r is the variable that is changing and is not held at a constant value.

For Example: R(c,r)= -57.496r² + 4275.432r - 59.247cr + 10,452.325c - 289.638c² so that: R_r = ∂R/∂r = -57.496(2r) + 4275.432(1)- 59.247c(1) + 0 - 0 In essence it would then be: = -114.992r + 4275.432 - 59.247c

We can use partial derivatives to estimate the partial rate of change of revenue with respect to regular sales, or, in general, we find the partial derivative of a multivariable function with respect to one input variabel by treating all other input variables as constants and proceeding to take derivatives as functions of a single input variable. For a two-variable function, a partial rate of change can be visualized graphically as the slope of a line tangent to a cross section.

(above was copied from Partial Derivatives; Using Partial Derivaties, deleted as part of cleanup, old spelling error that was copied over and over, here and there.... This talk page section may be deleted when no longer needed. Below is the content from the attached Talk page. --Abd 23:20, 28 July 2010 (UTC))

This page has to go. The title isn't right; the page Partial Derivative is the right place for this topic. When I have rescued the material here, I will have this page deleted.

Also, I was taught in 6^th grade not to define something with a sentence "XYZ is when .....".

SamHB 03:10, 20 July 2010 (UTC)