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(Math) |
An Introduction to
Generalized Calculus |
Unit II - Generalized Calculus |
Section B - Iterations from Anti-Iterations |
q [ f(x) dx ] 1/dx = f(x).
Now, we will do the reverse, compute the iteration from the anti-product limit, and show that:
[qf(x)1/dx] dx = f(x) c. (constant c).
recall qf(x)1/d = [f(x+d)/f(x)]1/d = [f(x)/f(x-d)]1/d (as d-->0)
when we multiply qf(x)1/d qf(x-d)1/d, the f(x-d)1/d terms cancel:
f(x)1/d
f(x-d)1/d |
f(x-d)1/d
f(x-2d)1/d |
= f(x)1/d
f(x-2d))1/d |
f(x)1/dx
f(x-d)1/d |
f(x-d)1/d
f(x-2d)1/d |
(x-d)1/d
f(x-2d)1/d |
... | (f -1(1)+d)1/d
f(f-1(1))1/d |
= f(x)1/d
f(f-1(1))1/d |
x
=
qf(x)1/d
f -1(1)
The specific f -1(1) limit was chosen because at this point, f(f-1(1)) = 1, and the right, expansion result above simplifies to:
[f(x)/f(f -1(1))]1/d = f(x)1/d. Therefore, appending the right side to the left yields:
x
qf(x)1/d = f(x)1/d.
f -1(1)
x
[qf(x)1/d] d = f(x)1/d. (raise both sides
to the dth power to get the origional equation.)
f -1(1)
Since (a..x) g(x)dx = (a..s) g(x)dx (s..x) g(x)dx = c (s..x) g(x)dx = c g(x)dx for some constant c,
x
[qf(x)1/d] d = f -1(1) |
c [qf(x)1/dx]dx |
The 2nd Derivative
Recall from the last section,
d2f(x)/dx2 = [ f(x+2dx) - 2f(x+dx) + f(x) ] / d2.
A double integral could be performed to get the inverse, but, instead,
a method similar to the above will be taken: