Discrete systems possible mistake in answers

[pokerfan91]

starting with the iterated map derived in the notes for calculating rootp(p>0)

X_n+1=1/2(X_n+(p)/(X_n)

calculate root 7 starting with x₀=1

so ok starting with that i get x0=1 x1=4 and then something strange happens the sub in looks like this

X₂=1/2(4+2/4)=9/4

i was under the assumption that this 2 would be a 7 as it is still the value of p?

 

[Dick]

Yes, it's a typo. x2=23/8.