thus we let
now we guess a root. let's say we're going after the one around 2.5. so we guess 2.5 (that is, we let )
you will get a value for
then repeat the same process, using the last value you got as , and keep doing it until you realize the values settling (you always get the same first three decimal places).
do this again for the other root, guess 0.5
below is the graph