The document discusses functions, sequences, logarithms, and sets. It defines functions as f(x)= and f(x)=2 and discusses V-shape and U-shape functions. It presents the sequence an=a1+(n-1)d and calculates the number of terms. It compares logarithms of different bases and determines an inequality is true. It defines sets A and B and operations including intersection, union, difference.

1. O-net
y = f(x)
1. f (x) =
2. f (x) =
3 f (x)
4 f (x)
-
V-Shape
(
V)
-
U-Shape (
U)
f(x) =
f (x) =
2
O-net
1. 1300
2. 1350
3. 1400
4. 1450
k
,3,5,…,49
k
, , ,…,
+1

2. 3
,
9( 57)
9
100
10,000
9
9
108,
117, 126, ..., 9,999
a1 = 108, an = 9,999
117 – 108 = 9
an = a1+ (n – 1)d
9,999 = 108 + (n – 1)9
9,891 = (n – 1)9
1,099 = n – 1
n = 1,100
1,100
10,000
4
9
100

3. “ONET”
( 57)
4.
“ONET”

4. 5 (
O-NET
2549, 2
3
100
10
310
1.
24
4.
2.
25
3.
26
27
a1 =100
d = +10
n
an = 310
a1
an =100 + (n −1)10
310 =100 + (n −1)10
3
3 + 22 = 25
a22
n = 22
24
3
1
1. 21000 < 3600 <10300
2. 3600 < 21000 <10300
3. 3600 <10300 < 21000
4. 10300 < 21000 < 3600

5. 21000
log21000 =1000log2 =1000(0.301) =
301
3600
log3600 = 600log3 = 600(0.48)
300
10300
log10300 = 300log10 = 300(1.00) =
300
3600 <10300 < 21000
U

6. A
B
x
B
A
3
2
3
∴
4
6
5

7. =
∴
6
7
12+35 = 47
100
6
∴
= 0.47
0.47
10. (
O-NET
A = { a, b, c }
2549, 2
)
B = { 0, 1 }
B
A
1. { (a,1), (b,0), (c,1) } 2. { (0,b), (1,a), (1,c) }

8. 3. { (b,1), (c,0) }
(
4. { (0,c), (1,b) }
)
B
A
B
A…
1
3
…
4
11. (
O-NET
2549, 2
)
A – B = { 2, 4, 6 }, B – A = { 0, 1, 3 }
A ∪ B = { 0, 1, 2, 3, 4, 5, 6, 7, 8 }
A ∩B
1. { 0, 1, 4, 5, 6, 7 }
2. { 1, 2, 4, 5, 6, 8 }
3. { 0, 1, 3, 5, 7, 8 }
4. { 0, 2, 4, 5, 6, 8 }
(
)
A ∩ B = (A ∪ B) – (A – B) – (B – A) …
A ∩ B = { 5, 7, 8 }
3
3
2