Question

Find the value of square root(72 + square root(72 + square root(72 + (...))) How do I do this?

Answer 1

If y=sqrt(72+sqrt(72+........)
then y=sqrt(72+y). As starting from the second square root the series is the same as y again.
y^2=72+y
y^2-y-72=0.
y-9)(y+8)=0. that means y=9.

Answer 2

Thank you