@murilofujita
Thank you for your explanation in this vídeo!
@YAWTon
x=(√34+√2)/√8 x=(√17+1)/2 [0] x is solution of x²-x-4=0 (by formula for quadratic equations), therefore x²=x+4 [1] x³=5x+4 [2] by multiplying RHS of [1] by x and substituting x² by RHS of [1] x⁶=65x+116 by squaring RHS of [2] and and substituting x² by RHS of [1] x⁶=(65√17+297)/2 by substituting RHS of [0] ifor x in RHS of .[3] Nice!
@dalestewart