Concept explainers
One important technique used to prove that certain sets not regular is the pumping lemma. The pumping lemma states that if
Want to see the full answer?
Check out a sample textbook solutionChapter 13 Solutions
DISCRETE MATHEMATICS+ITS APPL. (LL)-W/A
- 2. Recall that the Fibonacci sequence a₁, a2, a3,... is defined by a₁ = a₂ = 1 and An = An-1 + An-2 for all n ≥ 3. In this exercise, we will use determinants to prove the Cassini identity an+1ªn-1-a² = (−1)n for all n ≥ 2. Define suitable values for ao and a_1 so that the relation an = an−1 + An−2 holds for all n ≥ 1. (b) Let A = 01 (11) Show that an+k an+k+1= for all k-1 and all n ≥ 0. (c) Use (b) to show that An An+1 An-1 :) = = Then take the determinant on both sides to deduce the Cassini identity. = An An ak Ak+1 An ao a-1 a1 aoarrow_forward3. Suppose V is finite-dimensional and S, T are linear operators on V. Prove that ST is invertible if and only if S and T are both invertible.arrow_forwardLet B denote a Boolean algebra. Prove the identity V a, b e B, (a · b = 0) ^ (a + b = 1) = a = b. That is, prove the complement b is the unique element of B which satisfies (b · b = 0)^ (b + b = 1).arrow_forward
- b) Check whether the relation R on the set S = {1, 2, 3} with the the matrix 1 1 1 0 1 1 1 1 1 is an equivalence relation. Which of the following properties R has: reflexive, symmetric, anti-symmetric, transitive? Justify your answer in each case?arrow_forwardIf H is a Hilbert space and A € BL (H) is positive, prove that A+21 is invertible.arrow_forwardLet Z denote the set of integers. If m is a positive integer, we write Zm for the system of "integers modulo m." Some authors write Z/mZ for that system. For completeness, we include some definitions here. The system Zm can be represented as the set {0, 1,..., m - 1} with operations (addition) and (multiplication) defined as follows. If a, b are elements of {0, 1,..., m - 1}, define: ab the element c of {0, 1,...,m - 1} such that a +b-c is an integer multiple of m. a b = the element d of {0, 1,..., m - 1} such that ab -d is an integer multiple of m. For example, 30 4 = 2 in Z5, 303= 1 in Z4, and -1 = 12 in Z₁3. To simplify notations (at the expense of possible confusion), we abandon that new notation and write a + b and ab for the operations in Zm, rather than writing ab and a b. = Let Q denote the system of rational numbers. We write 4Z for the set of multiples of 4 in Z. Similarly for 4Z12. Consider the following number systems: Z, Q, 4Z, Z3, Z8, Z9, 4Z12, Z13. One system may be…arrow_forward
- Prove that the following relations are true in general: A₂=(A₁-A₂) U (A₂-A₁) a. A₁ + b. A₁ U (A₂ MA3)=(A₁ UA₂) N (A₁ UA3)arrow_forwardQ4. Let A = { 1, 2, 3, 4, 5, 6} and relation R on A defined by R = { (x.y)| (x+y) is a divisor of 24 } i) ii) iii) Find the relation matrix M of R Compute M2 Check whether R is transitive or notarrow_forward14. Study whether the following statements are true or false. Justify each answer. (Rememberthat if the statement is true a proof must be given while if the statement is falseIt is enough to give a counterexample).a) Let f be an endomorphism of R3 such that f3 = f2 ≠ 0. Then f has infinitely many invariant lines.b) Two matrices of M2(R) with the same trace and the same determinant are similar.c) Two endomorphisms of R3 with the same invariant lines and the same autovalues have the same real Jordan form.d) If A and M are square matrices whose squares are similar, A and M are also similar.e) Two endomorphisms with the same autovalues, the same nucleus and the same image, have similar matrices.f) Two real matrices that have the same real Jordan form can have different Complex Jordan forms.arrow_forward
- Make a logic circuit of the following Boolean Function. • F(x, y) = xy + x • F(x, y, z) = xz + xyarrow_forward13. Suppose that the relation R on the finite set A is rep- resented by the matrix MR. Show that the matrix that represents the symmetric closure of R is MR V M₂ 'R'arrow_forwarddarrow_forward
- Linear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage Learning