2-7 Square Roots & Real Numbers

Square Roots

√

• Remember:

2

5 =5 • 5

Five “squared”

Equals five times 5 !!!smart !! Trog getting Not feel sorry for self anymore!

The Square Root is just the opposite.

√ 16

Means: What number times itself equals 16 ? TROG KNOW!! So square root is 2 ! OHHH! Trog get it! 2 No times 8 equal 16 !!!! wait… ..because 4 times Square root 16 Square root is 8 of !....no itself equal 16 !! Is 4 be…Trog !! can’t Confused!!!

CALC LESSON

The square roots of some numbers are simple...

√ 49 = 7 √ = 9 81 √ 25 = 5

√9 4 √ 36 √

=3 =2 =6

Calculate this….

= 3.31662479… √ 11 A number with a non-repeating decimal is called irrational

GRAPHING REAL NUMBERS

1

2

3

4 5

x<5

6

7

GRAPHING REAL NUMBERS

64

65

66

67

68

x ≥ 65

69

70

GRAPHING REAL NUMBERS

1

2

3

4 5

6

7

y ≤ √45 y ≤ 6.70820….

Sometimes you are to find the negative square roots of some numbers….

-√ 49 = -7 -√ = -9 81 -√ 25 = -5

-√ 9 4 -√ 36 -√

= -3 = -2 = -6

Sometimes you are to find the negative square roots of some numbers….

±√ 49 = ± 7 ±√ = ±9 81 ±√ 25 = ± 5