Exercise 2.19 coordinates are incorrect.

[ncfausti]

On page 47 of the book, mini-project 2.19, solution says the coordinates are:

(2,4), (4,2), (2,4), and (4, -2)

Should be:

(-2,4), (-4,2), (2,4), and (4, -2)

Not sure if this is the right place to submit or not. Is there a public errata anywhere?