Lagrangian Interpolation

[Albert Chan]

(07-10-2024 05:09 AM)Thomas Klemm Wrote:  But because of the memory limitation of the HP-25 to only 8 registers,
the HP memory extension™ must be used. (See picture)

Can scrap paper work too?

Quote:In addition, the method is a bit tedious if the function is to be interpolated at several points.

We can use Acton Forman's method for polynomial coefficients too.

Instead of interpolating for a value, do divided difference (i.e. slope)

Code:

    X   Y      D   D^2
    2   4   
    3   9      5
  -11   121   -9   1

f(x) = 4 + (x-2)*(5 + (x-3)*1) = 4 + (x-2)*(x+2) = x^2