On this we calculate x1 as 2.5 times .2 minus

.2-squared which is equal to .4.

x2 is 2.5 times .4 minus .4-squared.

That's equal to .6. And x3 is equal to 2.5 times

.6 minus .6-squared and that's equal to

.6. Ah! They're the same. This is our fixed point

and b was the correct answer.