3.8 Finding and Es-ma-ng Square Roots
Vocab
square root -­‐
side length of a square, ie side length of a square = square root of the area of the square
the symbol,
square root
+
16 = 4 or -­‐4
principle square root -­‐
16 is 4, the posi-ve integer nega-ve square root -­‐
-­‐
16 is -­‐4, the nega-ve integer
radical sign -­‐
radicand -­‐
the number or expression under the radical sign
121
note -­‐ + indicates both posi-ve and nega-ve
, represents
Simplify each expression:
Thinking back . . .
Explain the difference between a ra-onal and an irra-onal number.
Iden-fy each expression as ra-onal of irra-onal:
perfect squares -­‐
squares whose side lengths are whole numbers
1 2
3
4
5
1
4
9
16
25
6
7
8
9
10
36
49
64
81
100
11
12
13
14
15
121
144
169
196
225
16
17
18
19
20
256
289
324
389
400
Between which two consecu-ve whole numbers do each of the following square roots fall?
27.9
114.4
311
234.5
404.04
3.8 Quick Check
Grade: 8th
Subject: Algebra
1 Simplify
√49
2 Simplify
-√196
3
The number below belongs to
which subset of the real number
system?
√294
A Rational
B Irrational
4
The number below belongs to which subset
of the real number system?
√169
A
Rational
B
Irrational
5 Between which
two consecutive
integers does
-√105
fall between?
p178: 1-48even