How to Calculate a sigma formula

Hello ,

I'm pretty much a novice at Excel functionality. I need to calculate a formula but not sure how to on excel.

So here's what I'd like to do:

I would like Excel to sum the "sigma" function SQRT(1-X^2)*1/X for X>0 but X<1

I need to do this to calculate an approximation of Pi using rectangles this formula will find the area and hence determine what Pi is for any number of rectangles


Is there any way Excel can accomplish this?

Are you sure formula is right?
Because already for x=2 you will have sqrt(1-2^2) ... = sqrt(-3)... so no such number (at least no such real number).

I sometimes think that spreadsheet users (maybe especially novice users??) try to make a single cell do too much. This calculation should be fairly easy -- if you spread it out over several cells. Here's how I would do it:

1) Have a column where I enter/calculate the desired x values. This might be as simple as entering the first few values, selecting these cells, then grab the little "plus" sign at the lower right corner of the selection and drag down as far as desired. Or enter the "step size" for you problem into a convenient cell (A1), enter the first entry (0) into A3, then a formula like =A3+$A$1. In this example, note the mix of relative and absolute references for easy copying (this was one of the first lessons I learned when working with spreadsheets -- an important one for novices to learn: https://support.office.com/en-us/art...rs=en-US&ad=US ).

2) With a column of x values, enter a formula to compute each added in an adjacent cell =SQRT(1-A3^2)/A3. Again note the relative references and copy down.

3) Finally, enter a =SUM(the range used in step 2) to get the final summation.

There's more that could be done, but for a novice, that should be a good starter lesson.