Point C is the golden section point (AC > BC) of line ab. if AB = 2, then AC = 2___ (denoted by root)

Point C is the golden section point (AC > BC) of line ab. if AB = 2, then AC = 2___ (denoted by root)

∵ AC > BC, ab = 2, ∵ BC = AB-AC = 2-ac, ∵ point C is the golden section of line AB, ∵ ac2 = ab · BC, ∵ ac2 = 2 (2-ac). After sorting out, ac2 + 2ac-4 = 0, the solution is AC = - 1 + 5, AC = - 1-5 (rounding off). So the answer is: - 1 + 5

If point a is the golden section point of line BC, then it is equal to AC / AB and speed

(√ 5-1) / 2 or (√ 5 + 1) / 2
That is to say, a line segment has two golden section points. If the small ratio is large, the former value and the large ratio is small

If AC: ab ≈ 0.618, then BC: AC ≈ 0.618

Ac:AB≈0.618
Ac:(Ac+cB)≈0.618/1≈0.618/(0.618+0.382)
Ac:(Ac+cB)≈0.618/(0.618+0.382)
Ac:cB≈0.618/0.382
Bc:AC≈0.382/0.618=0.191/0.309

What is the criterion of Weida theorem and equation root?

Weida theorem X1 + x2 = - B / a x1x2 = C / A
The discriminant of the equation Δ = the square of b-4ac
The equation with Δ > 0 has two unequal real roots
The equation Δ = 0 has two equal real roots
Δ