- #1
The Bob
- 1,126
- 0
Hello all,
I have been looking up the golden ratio and found most of what I needed on mathworld.
The site states that [tex]\phi \ = \ \frac{1}{2}(1+\sqrt{5})[/tex].
I can see how (despite the fact that I don't understand how the ratio:
[tex]\phi \ = \ \frac{AC}{BC} \ = \ \frac{AB}{AC}[/tex] is formed but that is another matter).
The problem I am having is turing this into either
[tex]\phi \ = \ 2 cos (\frac{\pi}{5})[/tex] or [tex]\phi \ = \ \frac{1}{2} sec (\frac{2 \pi}{5})[/tex].
Can anyone give me some hints please?
Cheers.
The Bob (2004 ©)
I have been looking up the golden ratio and found most of what I needed on mathworld.
The site states that [tex]\phi \ = \ \frac{1}{2}(1+\sqrt{5})[/tex].
I can see how (despite the fact that I don't understand how the ratio:
[tex]\phi \ = \ \frac{AC}{BC} \ = \ \frac{AB}{AC}[/tex] is formed but that is another matter).
The problem I am having is turing this into either
[tex]\phi \ = \ 2 cos (\frac{\pi}{5})[/tex] or [tex]\phi \ = \ \frac{1}{2} sec (\frac{2 \pi}{5})[/tex].
Can anyone give me some hints please?
Cheers.
The Bob (2004 ©)