Central Difference Approximation with VBA

**BFlick11** · 10-31-2010, 01:34 PM

Can someone answer this Question For me:

Write a function named SecondDerivative that returns the second derivative of the function at a specified x based on a central approximation. The function should take 2 arguements: the value of x where the derivative is to be evaluated and the value of DeltaX to be used for the central difference. Assume that the function is available in a VBA function termed myf(). myf() takes 1 arguement: the x value where the function is to be evaluated. For example, if the function is 3x^2+2x-1, then assume that the following code is already available:

Option Explicit
Function myf(x as double) as double
myf = 3*x^2+2*x-1
End Function

Thanks for any help,
Brandon

**martindwilson** · 10-31-2010, 01:39 PM

at this point we usually ask you to try for yourself,if the code doesn't work post it and ask for help!

**BFlick11** · 10-31-2010, 01:46 PM

I don't even know where to start, i've been looking at this thing for hours

**shg** · 10-31-2010, 03:45 PM

Brandon,

These are all homework questions. We will help if there are specific elements you don't understand, we will not do your homework for you.

Make an attempt, write some pseudocode, and then ask a specific question. Get some skin in the game.