The golden section law, also known as the golden section ratio, is to divide a known line segment into two parts, so that the ratio of one part to the whole is equal to the ratio of the rest. The most basic formula is to divide 1 into 0.6 18 and 0.382, and then change it into other calculation formulas according to the actual situation.

The golden section law was discovered by the great Greek mathematician Pythagoras in the 6th century BC. Its basic content can be explained as follows: if a line segment is divided into two parts, the ratio of the length of the long segment to the short segment is 1:0.6 18, and the ratio of the length of the whole line segment to the long segment is also 1:0.6 18, it is the most perfect division like gold, and this point for division is called gold.

The formula (50.5-1)/2 = (2.236-1)/2 = 0.618.

And then calculate

pq=2-(2-2*(5^0.5- 1)/2)*2=2*5^0.5-4