calculates fibbonacci (both ways) top one: F(n) = (F (n - 2) + F (n - 1)) bottom one: F(n) = (F (n - 1) * 1.618...) you can see how these get very recursive and slow if you try to calculate F(n) without first calculating the prior Fs there are pros and cons to both these methods top one + simple to make cuz of how similar it is to its English definition + more accurate - slower bottom one + faster - less simple (you need the golden ratio) - less accurate in conclusion, Fibonacci is very cool and very interesting it even shows up in pascals triangle (i think)
