CSCI 190 Exam I Practice

1)

a)Write the contrapositive of the following conditional statement

If it is raining, then the streets are wet.

b) Write the negation of the following:

Some Mt. SAC students are international students.

c)Express the following argument symbolically and determine if it is valid: If I study hard, then I get A’s or I get rich. I don’t get A’s and I don’t get rich. Therefore I didn’t study hard.

2)

Prove or disprove each of the following:

a)For the domain of real numbers,

b)For the domain of integers,

3)Prove that is odd if and only if is even.

4)Prove that if , then (hint: first pick . You need to show )

5)Prove that there is no largest integer.

6)

a)Show is

b)Show is not

7) Compute the Boolean Product for and

8)

a)Sketch for x in

b)Show defined as is onto. Justify your answer.

9) Find the close form (non-recursive form)of the recursive sequence ,

10)(2 points each: true/false, short answers: No partial credit points will be given. You are not required to show work.)

a)True/False: Let A, B be sets. If , then

b)True/False: for all real numbers x (including negatives)

c)True/False: Determine if the following statement is true or false: if and only if

d)Is the set of rational numbers countable or uncountable? ______

e)Is the set of real numbers countable or uncountable? ______

f)Rewrite the following sentence in “If P then Q” form. I pass CSCI 190 only if I study 10 hours a week.

______

g)Find the power set of ______

h)Find where ______

i)Compute ______

j)Find the nth term of the sequence ______

k)For defined by find and

l)Let A, B be matrices with C=AB. Find an expression for (using ) given

______

11)Prove if and , then for nonzero integers a,b,c.

12)Show is

13)

a)(1 point) True/False:

b)(1 point) True/False:

c)(2 points) Find the power set of

d)(2 points) For and , find

14)Find a non-recursive expression for

15)Determine if defined by is onto.

16)Prove that is logically equivalent to

17)Prove that if Prove that if , then for nonzero integers a,b,c.

18)Prove or disprove the following:

, where the domain is the set of all natural numbers 1, 2, 3, ….

19)Construct a truth table to determine if

20)Show that if then

21)Suppose x is a nonzero real number. Prove that if is an irrational number, then is also an irrational number.

22)Prove or disprove:

a)For the domain of real number

b)For the domain of real numbers,

23)Prove that there is no positive integer satisfying

24)(2 points each) Do NOT show work.

a)True/False

b)Write the negation of . Make sure the negation appears next to p(x,y)

c)Find an integer such that ______

d)For defined by , compute

e)Negate the following sentence: Nancy is tall and beautiful.

f)=______

g)What conclusion if any can be drawn from the following: If there is gas in the car, then I will not drink beer. If I drink beer, then I will go shopping. I did not go shopping.

h)For defined by , find

25)

a)(7 points) Find a formula (in closed form) for the recursive sequence

b)(3 points) Find the nth term of the sequence

26)Prove or disprove: , where the domain is the set of all real numbers.

27)Prove or disprove: defined by is a bijection.

28)For a function defined by , find a) b)

29)Prove that is irrational.

30)If is even, then is even or is even.

31)

a)Show

b)Show

c)Show

32)Prove that if , then for integers a,b,