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Number phi (φ)
The golden ratio is an irrational number with the value φ = 1.61803398874989…
Explanation
You can calculate the golden ratio as
With the quadratic formula you get
with as positive solution
and as negative solution
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As the numbers a and b are both positive, the negative solution is not valid.
HistoryThe letter φ (phi) is from the old Greek sculpter Phidias (490 - 430 BC), who wrote a book about the golden ratio. |