รากที่สอง

รากที่สอง

.
6310121204041

1 2565



1. 1
2. 1
3
2.1) 3
2.2) 5
2.3) 6
11
15

1. 1

a a a

1. 62 = 36 (-6)2 = 36
36 6 -6
6
-6 36
36

2. 112 = 121 (-11)2 = 121
121 11 -11

11 121
-11 121

3. 2 = 2=

4. (0.5)2 = 0.25 (-0.5)2 = 0.25
0.25 0.5 -0.5

0.5 0.25
-0.5 0.25

2

aa
a

a-

= =a =a -
- =- 36
=6
= -6

1 = 15
1) 225 = -15

225 = 15 x 15 15 -15
225
=
=
225

2) 0.0036 = 0.06
0.0036 = 0.06 x 0.06 = -0.06
0.0036
= 0.06 -0.06
=
0.0036

3

2.
2.1)

2
1) 1,269

1,296

1,269 = 4 x 4 x 9 x 9

1,269 = 4 x 9 x 4 x 9
1,269 1,269 = 36 x 36

1,296 = = 36

= = -36
1,296 36 -36

4

2) 48,400

48,400

48,400 = 2 x 2 x 11 x 11 x 10 x 10 = 220
48,400 = 2 x 10 x 11 x 2 x 10 x 11 = -220
48,400 = 220 x 220

48,400 =
=

48,400 220 -220

3 0.02
1) 0.02

0.02
0.02

2)

2.2) 5 ( 5
4 =5 2.2 2.3
x x2 = 5 )
22 = 4 32 = 9

2< <3

(2.1)2 = 4.41
(2.2)2 = 4.84
(2.3)2 = 5.29
2.2 < < 2.3

(2.22)2 = 4.9284
(2.23)2 = 4.9729
(2.24)2 = 5.0176

2.23 2.24
5 - 4.9729 = 0.0271
5.0176 5 = 0.0176
0.0176 < 0.0271

2.24 2.23
2.24

4

6

2.3)

7

8

9

10

1 222 222 = 484
n = 22

222 = 484

2 4.899
n = 24

4.899

3n 4.796

n = 23 4.796 n = 23

4 n n2 = 625 n = 25 n2
n = 25 252 = 625

5 n2 = 441
212 = 441 n = 21 n2
4.583
n = 21
4.583

6 3 4.690)
3= (

3 4.690

14.07
3 14.07

11

1 . 2 .... ..

:

1
14
256
499
625
0.01
0.49
5.76

12

2 . 2 .... ..

:

1) 1,521

2) 2,401

3) 3,429

13

2 () . 2 .... ..

4) 5,776

5) 6,561

14

3 . 2 .... ..

:
1)
2) 60
3) n n2 = 784
4) n 2.828
5) n2 = 5,776
6) n2 = 7,921
7) 2
8)
9) + +
10)

15

.2 . . ., https://www.saintlouis.or.th/article

/show/57e8e49b0478820001000004 [15 2565]

.2

2 [ ]. 2552, : http://academic.obec.go.th/textbook/web/images/book/

1552355345_example.pdf [15 2565].

. .2 [ ]. . . ., :

https://kanchit004.files.wordpress.com/2010/11/e0b8a0e0b8b2e0b884e0b89ce0b899e0b8a7e0b

8811.pdf [15 2565]