What are the special numbers! Such as golden section! PI! What are the special numbers! Such as golden section point 0.618! PI 3.14 It's better to have all of them

What are the special numbers! Such as golden section! PI! What are the special numbers! Such as golden section point 0.618! PI 3.14 It's better to have all of them

E is the base of natural logarithm, about 2.71828

How is 0.618 of golden section calculated?

There is a point P (AP > BP) on a line ab. we know that the line AB = L, Pb: AP = AP: ab. let the line AP = x, then the line Pb = l-x. from Pb: AP = AP: AB, we get the equation about X, i.e. l-x: x = X: LX & sup2; + lx-l2 = 0. The solution is x = - 1 ＋ 5 / 2 · l > 0, x = - 1 - √ 5 / 2 · l < 0