Linear Inequalities: Error in book?

1. Jan 1, 2008

Holocene

Give the interval notation for the inequality: $$\displaystyle{x\leq -2$$

My answer is: $$\displaystyle{(-\infty, -2]}$$

Book answer is: $$\displaystyle{(\infty, -2]}$$

?????

2. Jan 1, 2008

mathman

You're right. Looks like a typo in the book.

3. Jan 1, 2008

Holocene

Thanks. This book is absolutely riddled with errors of this type; enough to make you often doubt yourself after successfully completing some problems.

I hope the editor doesn't have any competition...

4. Jan 1, 2008

mathboy

When you read stuff like that you should know that it has to be a typo, because you know that it cannot make sense.