Evaluation of R(e−2π/5)
In the last post we established the transformation formula [[√5+12]5+R5(e−2α)][[√5+12]5+R5(e−2β)]=5√5[√5+12]5 under the condition αβ=π2/5.If we put α=π then β=π/5 and since we already know the value of R(e−2π) we can use equation (1) to evaluate R(e−2π/5). But in order to do that we need to calculate R5(e−2π) first.
We have from an earlier post R(e−2π)=√5+√52−√5+12