Chapter 3

Discrete Mathematics with Applications · 390 exercises

Problem 27

Let \(\mathrm{A}, \mathrm{B},\) and \(\mathrm{C}\) be any \(m \times n\) matrices, \(O\) the \(m \times n\) zero matrix, and \(c\) and \(d\) any real numbers. Prove each (see Theorem 3.12 ). $$A+B=B+A$$

4 step solution

Problem 27

Let \(U=\\{\mathrm{a}, \ldots, \mathrm{h}\\} .\) Characteristic function \(f_{S}\) is given as an 8 -bit word. Find the corresponding set \(S .\) $$11010100$$

3 step solution

Problem 28

Evaluate each sum, where \(\delta_{i j}\) is defined as follows. $$ \delta_{i j}=\left\\{\begin{array}{ll}{1} & {\text { if } i=j} \\ {0} & {\text { otherwise }}\end{array}\right. $$ \(\left[\delta_{j} \text { is called Kronecker's delta, after the German mathematician Leopold }\right.\) Kronecker \((1823-1891) . ]\) $$ \sum_{i=1}^{5} \sum_{j=1}^{5} \delta_{i j} $$

5 step solution

Problem 28

Let \(f: \mathbf{Z} \times \mathbf{Z} \rightarrow \mathbf{Z}\) defined by \(f(x, y)=2 x+3 y-6 x y .\) Compute the following. $$f(-3,-5)$$

2 step solution

Problem 28

Let \(U=\\{a, \ldots, h\\} .\) In Exercises \(27-30,\) a characteristic function \(f_{S}\) is given as an 8 -bit word. Find the corresponding set \(S\) . $$00101101$$

3 step solution

Problem 28

Let \(\mathrm{A}, \mathrm{B},\) and \(\mathrm{C}\) be any \(m \times n\) matrices, \(O\) the \(m \times n\) zero matrix, and \(c\) and \(d\) any real numbers. Prove each (see Theorem 3.12 ). $$A+(B+C)=(A+B)+C$$

4 step solution

Problem 28

Let \(U=\\{\mathrm{a}, \ldots, \mathrm{h}\\} .\) Characteristic function \(f_{S}\) is given as an 8 -bit word. Find the corresponding set \(S .\) $$00101101$$

3 step solution

Problem 29

Evaluate each sum, where \(\delta_{i j}\) is defined as follows. $$ \delta_{i j}=\left\\{\begin{array}{ll}{1} & {\text { if } i=j} \\ {0} & {\text { otherwise }}\end{array}\right. $$ \(\left[\delta_{j} \text { is called Kronecker's delta, after the German mathematician Leopold }\right.\) Kronecker \((1823-1891) . ]\) $$ \sum_{i=1}^{3} \sum_{j=1}^{5}\left(2+3 \delta_{i j}\right) $$

4 step solution

Problem 29

Let \(A, B,\) and \(C\) be any \(m \times n\) matrices, \(O\) the \(m \times n\) zero matrix, and \(c\) and \(d\) any real numbers. Prove each (see Theorem 3.12). $$A+O=A=O+A$$

4 step solution

Problem 29

Mark each sentence as true or false. Assume the composites and inverses are defined: Every invertible function is injective.

3 step solution

Problem 29

Let \(\Sigma\) denote the English alphabet. Let \(g: \Sigma^{*} \rightarrow \Sigma^{*}\) defined by \(f(w)=\) awa. The function prefixes and suffixes each word with a. Find \(f(w)\) for each word \(w\). zale

2 step solution

Problem 29

Let \(U=\\{a, \ldots, h\\} .\) In Exercises \(27-30,\) a characteristic function \(f_{S}\) is given as an 8 -bit word. Find the corresponding set \(S\) . $$10101010$$

3 step solution

Problem 29

Let \(\mathrm{A}, \mathrm{B},\) and \(\mathrm{C}\) be any \(m \times n\) matrices, \(O\) the \(m \times n\) zero matrix, and \(c\) and \(d\) any real numbers. Prove each (see Theorem 3.12 ). $$A+O=A=O+A$$

4 step solution

Problem 29

Let \(U=\\{\mathrm{a}, \ldots, \mathrm{h}\\} .\) Characteristic function \(f_{S}\) is given as an 8 -bit word. Find the corresponding set \(S .\) $$10101010$$

3 step solution

Problem 30

Evaluate each sum, where \(\delta_{i j}\) is defined as follows. $$ \delta_{i j}=\left\\{\begin{array}{ll}{1} & {\text { if } i=j} \\ {0} & {\text { otherwise }}\end{array}\right. $$ \(\left[\delta_{j} \text { is called Kronecker's delta, after the German mathematician Leopold }\right.\) Kronecker \((1823-1891) . ]\) $$ \sum_{i=1}^{6} \sum_{j=1}^{7}\left(i^{2}-3 i+\delta_{i j}\right) $$

4 step solution

Problem 30

Let \(A, B,\) and \(C\) be any \(m \times n\) matrices, \(O\) the \(m \times n\) zero matrix, and \(c\) and \(d\) any real numbers. Prove each (see Theorem 3.12). $$(-1) A=-A$$

6 step solution

Problem 30

Mark each sentence as true or false. Assume the composites and inverses are defined: Every invertible function is surjective.

3 step solution

Problem 30

Let \(\Sigma\) denote the English alphabet. Let \(g: \Sigma^{*} \rightarrow \Sigma^{*}\) defined by \(f(w)=\) awa. The function prefixes and suffixes each word with a. Find \(f(w)\) for each word \(w\). mbrosi

2 step solution

Problem 30

Let \(U=\\{a, \ldots, h\\} .\) In Exercises \(27-30,\) a characteristic function \(f_{S}\) is given as an 8 -bit word. Find the corresponding set \(S\) . $$01010101$$

4 step solution

Problem 30

Let \(U=\\{\mathrm{a}, \ldots, \mathrm{h}\\} .\) Characteristic function \(f_{S}\) is given as an 8 -bit word. Find the corresponding set \(S .\) $$01010101$$

4 step solution

Problem 31

Just as \(\sum\) is used to denote sums, the product \(a_{k} a_{k+1} \ldots a_{m}\) is denoted by \(\prod_{i=k}^{m} \mathrm{a}_{i} .\) The product symbol \(\Pi\) is the Greek capital letter \(p i .\) For example, \(n !=\prod_{i=1}^{n} i .\) Evaluate each product. $$\prod_{i=1}^{3}(i+1)$$

4 step solution

Problem 31

Let \(A, B,\) and \(C\) be any \(m \times n\) matrices, \(O\) the \(m \times n\) zero matrix, and \(c\) and \(d\) any real numbers. Prove each (see Theorem 3.12). $$c(A+B)=c A+c B$$

6 step solution

Problem 31

Mark each sentence as true or false. Assume the composites and inverses are defined: Every invertible function is bijective.

3 step solution

Problem 31

Let \(\Sigma\) denote the English alphabet. Let \(g: \Sigma^{*} \rightarrow \Sigma^{*}\) defined by \(f(w)=\) awa. The function prefixes and suffixes each word with a. Find \(f(w)\) for each word \(w\). rom

4 step solution

Problem 31

Find the day of the week in each case. 234 days from Monday

3 step solution

Problem 31

Student records are maintained in a table using the hashing function \(h(x)=x \bmod 9767,\) where \(x\) denotes the student's social security number. Compute the location in the table corresponding to the given key, where the record is stored. $$012-34-5678$$

4 step solution

Problem 31

Let \(\mathrm{A}, \mathrm{B},\) and \(\mathrm{C}\) be any \(m \times n\) matrices, \(O\) the \(m \times n\) zero matrix, and \(c\) and \(d\) any real numbers. Prove each (see Theorem 3.12 ). $$c(A+B)=c A+c B$$

2 step solution

Problem 31

Find the day of the week in each case. 234 days from Monday

2 step solution

Problem 32

Student records are maintained in a table using the hashing function \(h(x)=x \bmod 9767,\) where \(x\) denotes the student's social security number. Compute the location in the table corresponding to the given key, where the record is stored. $$876-54-3210$$

4 step solution

Problem 32

Just as \(\sum\) is used to denote sums, the product \(a_{k} a_{k+1} \ldots a_{m}\) is denoted by \(\prod_{i=k}^{m} \mathrm{a}_{i} .\) The product symbol \(\Pi\) is the Greek capital letter \(p i .\) For example, \(n !=\prod_{i=1}^{n} i .\) Evaluate each product. $$\prod_{j=3}^{5}\left(j^{2}+1\right)$$

3 step solution

Problem 32

Let \(A, B,\) and \(C\) be any \(m \times n\) matrices, \(O\) the \(m \times n\) zero matrix, and \(c\) and \(d\) any real numbers. Prove each (see Theorem 3.12). $$(c d) A=c(d A)$$

3 step solution

Problem 32

Mark each sentence as true or false. Assume the composites and inverses are defined: Every bijection is invertible.

3 step solution

Problem 32

Let \(\Sigma\) denote the English alphabet. Let \(g: \Sigma^{*} \rightarrow \Sigma^{*}\) defined by \(f(w)=\) awa. The function prefixes and suffixes each word with a. Find \(f(w)\) for each word \(w\). nesthesi

4 step solution

Problem 32

Find the day of the week in each case. 365 days from Friday

4 step solution

Problem 32

Let \(\mathrm{A}, \mathrm{B},\) and \(\mathrm{C}\) be any \(m \times n\) matrices, \(O\) the \(m \times n\) zero matrix, and \(c\) and \(d\) any real numbers. Prove each (see Theorem 3.12 ). $$(c d) A=c(d A)$$

5 step solution

Problem 32

Find the day of the week in each case. 365 days from Friday

4 step solution

Problem 33

Just as \(\sum\) is used to denote sums, the product \(a_{k} a_{k+1} \ldots a_{m}\) is denoted by \(\prod_{i=k}^{m} \mathrm{a}_{i} .\) The product symbol \(\Pi\) is the Greek capital letter \(p i .\) For example, \(n !=\prod_{i=1}^{n} i .\) Evaluate each product. $$\prod_{j=-5}^{50} 1$$

3 step solution

Problem 33

Let \(A, B,\) and \(C\) be any square matrices of order \(2 .\) Prove each. $$A(B C)=(A B) C$$

3 step solution

Problem 33

Mark each sentence as true or false. Assume the composites and inverses are defined: The composition of two invertible functions is invertible.

5 step solution

Problem 33

Find the day of the week in each case. 1776 days from Wednesday

4 step solution

Problem 33

Find the day of the week in each case. 1776 days from Wednesday

3 step solution

Problem 34

Just as \(\sum\) is used to denote sums, the product \(a_{k} a_{k+1} \ldots a_{m}\) is denoted by \(\prod_{i=k}^{m} \mathrm{a}_{i} .\) The product symbol \(\Pi\) is the Greek capital letter \(p i .\) For example, \(n !=\prod_{i=1}^{n} i .\) Evaluate each product. $$\prod_{k=0}^{50}(-1)^{k}$$

5 step solution

Problem 34

Let \(A, B,\) and \(C\) be any square matrices of order \(2 .\) Prove each. $$A(B+C)=A B+A C$$

5 step solution

Problem 34

Find the day of the week in each case. 2076 days from Saturday

3 step solution

Problem 34

Find the day of the week in each case. 2076 days from Saturday

3 step solution

Problem 35

Store the following two-letter abbreviations of states in the United States in a hash table with 26 cells, using the hashing function \(h(x)=\) first letter in \(x:\) $$ \mathrm{NY}, \mathrm{OH}, \mathrm{FL}, \mathrm{AL}, \mathrm{MA}, \mathrm{CA}, \mathrm{MI}, \mathrm{AZ} $$

4 step solution

Problem 35

Evaluate each sum and product, where \(p\) is a prime and \(I=\\{1,2,3,5\\}.\) $$\sum_{k=0}^{3} k !$$

2 step solution

Problem 35

Let \(A, B,\) and \(C\) be any square matrices of order \(2 .\) Prove each. $$(A+B) C=A C+B C$$

5 step solution

Problem 35

Let \(S=\\{\text { true, falsel. Define a boolean function } f : \mathbb{N} \rightarrow S \text { by } f(n)=\text { true }\) if year \(n\) is a leap year and false otherwise. Find \(f(n)\) for each year \(n .\) $$1996$$

4 step solution

Problem 35

Let \(S=\\{\text { true, false }\\} .\) Define a boolean function \(f: \mathbb{N} \rightarrow S\) by \(f(n)=\) true if year \(n\) is a leap year and false otherwise. Find \(f(n)\) for each year \(n\). $$1996$$

3 step solution

Show/ page