[Ether]

Originally Posted by phargo#1018

I appreciate the inquiry. Algebra always seems to be a challenge.
Today I started with the equation from page 20 and the assumption that I had improperly derived the equations on page 21.

Attached is the work.
Based upon this,I believe that I correctly provided the equations on page 21.

I agree. I should have been clearer. My intended meaning was that the equations on page 21 do not obviously follow from direct substitution into the J₂ = J₁ * (T₂² - T₁²) / T₁² equation on page 20.

Here's another way to derive the necessary equations.