Section 2-8 Definitions Square root: = 6. Radical sign: This is a radical sign. Perfect square: 4, 9, 16, 25, … are perfect square numbers. Because 2*2=4, 3*3=9, 4*4=16, 5*5=25, …

Section 2-8 definitions cont. Irrational number: is a number that cannot be expressed in the form of which is a fraction. Example: = …, since this is not a repeating or terminating decimal, this number is irrational. Real numbers: are the set of rational and the set of irrational numbers together. See whiteboard Venn diagram See whiteboard Venn diagram

Section 2-8 examples Find the following square roots: 1.) 2.) - 3.) 1.) 2.) - 3.) Answers: 1.) 4 2.) -7 3.) 11 Answers: 1.) 4 2.) -7 3.) 11 Name the set or sets of numbers which each number belongs to. Use N for natural numbers, W for whole numbers, Z for integers, Q for rational Numbers, and I for irrational numbers. 4.) - 5.) 0 6.) 8/4 4.) - 5.) 0 6.) 8/4 Answers: 4.) Z, Q 5.) W, Z, Q 6.) N, W, Z, Q Answers: 4.) Z, Q 5.) W, Z, Q 6.) N, W, Z, Q