psyche

Those other things are still up (plotter, graphics, recursion) and this is an Excel spreadsheet which I used to do a bunch of simultaneous equations to determine that the sum from r=1 to n of r⁴ is n⁵/5 + n⁴/2 + n³/3 - n/30. I’ll simplify that later I suppose.

The idea was that the sum of r^p can be expressed as a polynomial of order p + 1, so I just got 5 simultaneous equations involving the 5 coefficients of the quintic expression and got Excel to solve them in an “algorithmic” way similar to the triangular form thing we have to do.

I was revising FP1 and the sections on triangular form and summations of r^p “inspired” me to do this.

Pax