Minimizing c2, cont’d.
Here are our two equations, rearranged. Note that all the quantities in
parentheses can be computed directly from our data, so they are
just numbers.
Using linear
algebra or matrix
techniques, it
is simple to invert
these
equations to find A and B.
I won’t do it
here, but will just
write the
answer.
This is
exactly what is done in
Linfit.xls, by
the way, and you can look at it
By opening the
file, clicking on “Tools”, then “Macros”, then the
Linfit macro,
then “Edit”. The Linfit macro is
written in Basic and is relatively easy to follow.
The answer is:
