This MitPY comes from frequent commenter, John Friend:
I gave a CAS-FREE question to my Specialist students whose first part was to solve (exactly) the equation . I solved it two different ways and got two different answers that are equivalent. I’ve attached my calculations.
I checked my answers using Mathematica, which lead to my question: Mathematica gives a third different but equivalent answer (scroll down to real solutions). How has Mathematica got this answer?
It may be that Mathematica ‘used’ my Method 2, got my tan answer and then for some arcane reason ‘manipulated’ this answer into the one it finally gives. If so, I can ascribe the answer to a Mathematica quirk. But it may be that Mathematica is using a method unclear to me that leads to its answer. If so, I’m curious.
Any thoughts are appreciated.