In Class Exercise: 1	Jan 10, 2008	


Prove the following theorems:

1. if x >= 5, then x^2 >= 20.

2. if x <= 5, then x^2 <= 20.

3. What type of proof is the diagonalization ones in the last class?

For the following relations between sets A and B mention 
if they are partial function, total function, one to one 
and/or onto:

A={a, b, c} B={1, 2}

	RELATIONS		PF	TF	1-1	Onto
	---------		--	--	---	-----
4. {(a, 1), (b, 1), (c, 1)}	T/F	

5. {(a, 2), (b, 2)}

6. {(a, 1), (a, 2)}

7. {(a, 2), (b, 1), (c, 2)}

A={a, b, c} B={4, 5, 6}

8. {(a, 5), (c, 4), (b, 6)}

9. {(a, 5), (b, 5), (c, 6)}

10. {(a, 4), (b, 5), (b, 6)}