Lesson 3
1. Lesson 3
1.8. Explore 4
Module 5: Radicals
Try This 4
When you square a negative number, the result is positive; for example, (−5)2 = 25. However, the square-root sign indicates only the absolute value of the square root; 
, not −5.
How do you indicate that you want the negative root? How do you indicate that you want both the negative and the positive root?
- Use symbols to indicate that you want only the negative root of x2.
- Use symbols to indicate that you want both the negative and positive roots of y4.
Self-Check 3
Practise your new skills in Positive and Negative Roots.
Skip forward to Connect if you feel you have a solid understanding of how to
- simplify expressions with radical denominators by rationalizing the denominator
- explain the rules for writing positive and negative roots, including the idea that the square root of a number squared refers to the absolute value of that number
If you need a bit more practice, complete Self-Check 4.
Self-Check 4
Complete any or all of questions 2, 4, 5, 6.d., 8, 11, and 15 on pages 289 to 291 in the textbook. As you finish each part of a question, check your work against the answers given at the back of the textbook. If you are still unclear about how to answer some questions, ask your teacher about those questions and get some help.
Put the negative or positive symbol on the radical, not just on the root.