From 11:00PM PDT on Friday, July 1 until 5:00AM PDT on Saturday, July 2, the Shmoop engineering elves will be making tweaks and improvements to the site. That means Shmoop will be unavailable for use during that time. Thanks for your patience!
Because a negative number squared gives you a positive result, y could be 3 or -3. Plugging either value into the equation in place of the y will give you the proper solution.
For what values of y is |y| ≤ 1?
This problem is asking what numbers are within 1 unit of 0 in either direction on the number line. Remember, those vertical lines surrounding a number are asking for its absolute value. When you've got a number surrounded, it'll pretty much tell you anything you want to know. In this case, y can be any real number between -1 and 1. In symbols, the answer to this problem is -1 ≤ y ≤ 1.