Variables as Unknown Quantities Examples Page 2

For what values of y is |y| ≤ 1?

This problem is asking what numbers are within 1 of zero in either direction on the number line. Remember, those vertical lines surrounding a number are asking for its absolute value. When you have got a number surrounded, it will 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.