Warm-Up
• Find the perfect squares. No calculators!
1× 1 = 1 = 1
2
2× 2 = 2 = 4
2
3× 3 = 3 = 9
2
• Keep going to 15!!!
Objectives
The student will be able to:
1. simplify square roots, and
2. simplify radical expressions.
If x2 = y then x is a square root of y.
In the expression 64 ,
is the radical sign and
64 is the radicand.
Now you try!
1. Find the square root: 64
8
2. Find the square root: − 0.04
-0.2
3. Find the square root: ± 121
11, -11
4. Find the square root:
21
5. Find the square root: −
5
−
9
441
25
81
6. Use a calculator to find each
square root. Round the decimal
answer to the nearest hundredth.
± 46.5
6.82, -6.82
Evaluating a Radical Expression
Evaluate b − 4ac when a = 1, b = −2 ,
and c = −3 .
2
(− 2)
2
− 4(1)(− 3)
4 + 12
16
4
Evaluate b − 4ac when a = 7, b = 8 ,
and c = 1 .
2
(8)
2
− 4(7 )(1)
64 − 28
36
6
Evaluating an Expression with a Calculator
Evaluate 1± 2 3 to the nearest hundredth.
4
This is really TWO different numbers:
1+ 2 3
4
1.12
1− 2 3
4
− 0.62
Evaluate 1 ± 2 6 to the nearest hundredth.
−4
This is really TWO different numbers:
1+ 2 6
−4
1− 2 6
−4
− 1.47
0.97
Practice!!!
1. − 81
2. 49
3. ± 100
4. − − 0.04
5. − 12
1.
2.
3.
4.
5.
−9
7
± 10
Undefined
− 3.46
− b ± b − 4ac
; a = 6, b = −2, c = −1.
2a
2
Evaluate
0.61, -0.27
Homework: p507 #24-52 evens (15 problems)