Re: How Do I Invert These Two Functions



On Wed, 28 Nov 2007 23:23:02 GMT, John Schutkeker
<jschutkeker@xxxxxxxxxxxxxxxxxxxx> wrote:


If I define u1(r1,r2)=(1/r1)+(1/r2) and u2(r1,r2)=1/(r2-r1). How would I
go about solving these two equations for r1(u1,u2) and r2(u1,u2), which
would constitute "inverting the functions"? Thanks In Advance!

Elementary algebra! Try it before giving up.

Write down 2 equations:

u1 = (1/r1)+(1/r2)

u2 = 1/(r2-r1)

Viewing r1,r2 as the unknowns, you have 2 equations in 2 unknowns.

How hard can it be?

Of course, there are always tricks, but before looking for tricks, how
about trying the most basic method (from elementary algebra):

Choose one equation and solve that equation for one of the unknowns in
terms of the other. Then use the result as a replacement for that
unknown in the other equation, thus yielding one equation in one
unknown. You should be able to figure out the rest.

You try it.

quasi
.



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