x : = : x x
x :1 = 1: x 1
x : = : x x : = : x x : = : x x ( x ) = x = x x = + x x = + + x x = + + + + x = + + + + +L x
x :1 = 1: x 1 x ( x 1) = 1 x 2 x =1 x 2 x 1= 0 1± 1+ 4 x = 2 = 1 ± 5 2 x > 1 x = 1+ 5 2 x =1.6180339
d 10 3d 17.5d