PROBLEM*: Cos 36 degrees
(a) Express 
in closed form. See Sublime Triangle.
(b) Prove that 
What is "closed form?" Express as a real
number. Not a decimal approximation. Not the sum of some infinite
series.
Hint?
One solution.
Alternative solutions?
Interpretations of either (a) or (b)?
See also 
Return to the EMAT
4600/6600 Page.
* This is problem 4409 in School Science and
Mathematics, proposed by Herta T. Freitag, Roanoke, VA.