147 Answered Questions for the topic discrete mathematics

10/08/15

#### Properties of Divisibility

Let a, b, and c be integers with a≠0. Prove that if a|b then ab|c.

10/08/15

#### Properties of Divisibility

Let a, b, and c be integers with a≠0. Prove that if a|b and b|c then a|c.

09/23/15

#### Find a closed form for these summations?

Find a closed form for these summations?     n=100a) ∑ 1/2     i=1      n=5b) ∑ 1/3     i=1

09/23/15

#### Find a closed form for these summations?

Find a closed form for these summations?     n=10000    ∑ i    i=1

09/22/15

#### Finding a closed form for these summations?

Find a closed form for these summations?       n=10000 a) ∑ i     i=1        n=100b) ∑ i2    i=1

09/22/15

#### We have to recurrence relation an = 2an-1 - an-2. Find a2 and a3 if

We have to recurrence relation an = 2an-1 - an-2. Find a2 and a3 if:   a) a0 = 1 og a1 = 0?   b) a0 = 0 og a1 = 1?   c) a0 = 1 og a1 = 2?

09/22/15

#### Solve this recurrence relation and find a2 and a3?

We have to recurrence relation an = 2an-1 - an-2. Find a2 and a3 if:   a) a0 = 1 and a1= 1? b) a0 = 0 and a1 = 0?

09/22/15

#### Finding a closed form for these summations?

Find a closed form for these summations?     n=100 a) ∑ 1/2    i=1           n=5b)  ∑ 1/3     i=1

08/25/15

#### Can anyone help me with this? I'm suppose to use resolution to prove that [(p ? q) ^ (q ? (r ^ s))] ? (p ? s)

I have to use resolution to prove these inferences are valid [(p → q) ^ (q → (r ^ s))] → (p → s) ?

06/07/15

#### prove that for every 8 choosen numbers from 10 to 36 you can always make equalities.

number can be used once. examples. let say that the choosen numbers are 10, 11, 12, 15, 18, 25, 32, 36 you can write 11+25=36 or 10+12+18=15+25. i tried to prove for summation for every 2 numbers... more

05/25/15

#### There exists a set S such that the number of function f : S ?{1,2,3} is 1000

There exists a set S such that the number of function f : S →{1,2,3} is 1000 true or false, please provide with explanation.

05/17/15

#### Prove that for any integer n, with n greater than or equal to 1...

Using mathematical induction, prove that for any integer n, with n≥1, n(n2-1)(n+2) is divisible by 4.

04/29/15

#### A group to be surveyed is randomly selected from employees who have been with the company for 5 years. Name the type of sampling used and is the sample biased?

A company conducts a survey every spring to measure the morale of its employees. A group to be surveyed is randomly selected from all employees who have been with the company for exactly 5 years.... more

04/11/15

#### What is the Largest Input Size?

Suppose a machine on average takes 108 seconds to execute a single algorithm step. What is the largest input size for which the machine will execute the algorithm in 2 seconds assuming the number... more

03/24/15

#### Discrete Math Question??

There are 40 students in their first year of Computer Science program. All of these students must take either Discrete Math or Statistics, or both. There are 28 students in total taking Discrete... more

03/12/15

#### Prove that 1·1!+2·2!+···+n·n!=(n+1)!-1 whenever n is a positive integer. Mathematical Induction.

This is a problem that is supposed to use mathematical induction. I know how to create the basis case, and create the assumption using "k" but as soon as you are supposed to prove for "k+1" i am... more

02/20/15

#### Prove A is contained in B knowing: A = {x I x=4s-1 for some s is an integer} and B = {x I x=2t-1 for some t is an integer}

Prove A is contained in B   We know:   A = {x I x=4s-1 for some s is an integer} B = {x I x=2t-1 for some t is an integer}   Not even sure where to start, thanks for the help!

02/20/15

I have tried direct proof and proof by contradiction. Prove: 3(√2)-5 is irrational given that √2 is irrational Thats pretty much it, I have had a few starts but they dont go anywhere.

02/06/15

Suppose you are to prove the statement "The difference of any two odd integers is even." Re-write this statement as a universal conditional statement. What should the first sentence of a direct... more

11/07/14

#### Find all integer m ..

Find all integer m such that 1848 Ξ 1914 (mod m) ? Explain.

10/21/14

#### Is the function injective or surjective?

Determine whether the function f: NxN --> Z with f(x,y) = (1-x^2)[y/3] is either:   a) injective b) surjective       Injective function A function f is said to be one-to-one, or... more

10/21/14

#### Show that the function f: N * N - > N * N, f(x,y) = (x+y, 2x-3y) is one-to-one.

Show that the function f: N x N - > N x N, f(x,y) = (x+y, 2x-3y) is one-to-one.(A function f is said to be one -to -one , or injective , if and only if f ( a) = f ( b ) implies that a = b for... more

08/16/14

#### recurrence relation

Find the solution of recurrence relation  an+1-an-1 = 2an for n ≥ 0 and satisfying initial conditions of a0=3 and a1=3.

05/18/14

#### .: Let R={3,4,5,6,7,8,9} ,S={1,3,5} and T={ 2,4,6,8} a) R n S b) R – T c) S ? T

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05/18/14

#### Which relationships are true? Hint: the List of symbols in the front cover will help) a) Q ? Z b) Q ? Z = Q c) Z^+ U Q =Z

efj24fjj234 k4hihf4hf brh45oftho45t 5hgfih5it5 g5jgij5t 5tkj5igj5ft n54fgjo5j4f 5

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