3

6

9

12

{(5,3)}

{(3,5)}

{(5,5) , (3,3)}

{(5,5) , (5,3) , (3,5) , (3,3)}

{(3,2) , (1,–3)}

{(3,–3 ) , (1,2)}

{(3,2) , (3,–3) , (1,2) , (1,–3)}

{(2,3) , (–3,3) , (2,1) , (–3,1)}

A x B อ่านว่า เอ คูณ บี

A x B = { (a , b) | a ∈ A และ b ∈ B }

(a,b) = (c,d) ก็ต่อเมื่อ a = c และ b = d

A x B = B x A เสมอ

r = {(0,1) , (0,2)}

r = {(2,0) , (2,1)}

r = {(0,2) , (0,1)}

r = {(1,0) , (2,0)}

r = { (x,y) $\epsilon$ A x A | x = $\left\{\sqrt{y}\right\}$

r = { (x,y) $\epsilon$ B x B| x = $\left\{\sqrt{y}\right\}$

r = { (x,y) $\epsilon$ A x B | x = $\left\{\sqrt{y}\right\}$

r = { (x,y) $\epsilon$ B x A | x = $\left\{\sqrt{y}\right\}$

D_r = {2, 3}

D_r = {2, 3, 4, 5}

D_r = {5, 6}

D_r = {5, 6, 7, 8}

D_r = { y | y ≥ 0 }

D_r = { x | x ≥ 0 }

D_r = R

D_r = I

D_r = { x | -2 ≤ x ≤ 2 }

D_r = { x | x ≥ 1 }

D_r = { x | x ≥ 0 }

D_r = R

Dr = { x | -2 ≤ x ≤ 2 }

Dr = { x | x ≥ 2 }

Dr = { x | x ≥ 0 }

Dr = R

{(x,y) | y = 3x}

{(x,y) | y = -5x+1}

{(x,y) | y= $1-2x$ }

{(x,y) | $y^2=x^2-4$ }

ข้อ 1,4

ข้อ 1,2,3

ข้อ 2,3

ข้อ 2,3,4

0

-1

1

2

f + g = {(3,-1),(4,-6)

f + g = {(3,9),(4,8),(5,14)}

f + g = {(3,1),(4,6),(5,2)}

f + g = {(3,9),(4,8)}

7

8

11

12

gof = {(2,3),(3,2),(4,1)}

gof = {(4,9),(9,4)}

gof = {(3,2),(2,3),(1,4)}

gof = {(9,4),(4,9)}

gof = {(2,3),(3,2),(4,1)}

gof = {(4,9),(9,4)}

gof = {(3,2),(2,3),(1,4)}

gof = {(9,4),(4,9)}

5

-5

9

-9

Dr = ( 1 , ∞ ) , Rr = ( -∞ , ∞ )

Dr = [ 1 , ∞ ) , Rr = ( -∞ , ∞ )

Dr = [ 1 , ∞ ) , Rr = [0 , ∞ )

Dr = [ 1 , ∞ ) , Rr = (0 , ∞ )

Dr =  R - {0}

Dr =  { x | x ≥ 0 } 

 Dr =  R

Dr       =        R - {1}