Chapter 10.7, Problem 10P

B\ Prove that if T is a spanning tree of G which contains e, then Te Is a spanning tree of G * e.

9 Q/ Let G be agraph with n vertices, then G has at least two vertices which are not cut vertices.

Find the first four nonzero terms in a power series expansion about x=0 for a general solution to the given differential equation w''-14x^2w'+w=0

In this exercise, we will investigate a technique to prove that a language is notregular. This tool is called the pumping lemma.The pumping lemma says that if M = (S, I, f, s0, F ) is a DFA with p states (i.e., p = |S|) and if the wordw is in L(M ) (the language generated by M ) and w has length greater than or equal to p, then w may bedivided into three pieces, w = xyz, satisfying the following conditions:1. For each i ∈ N, xy^i z ∈ L(M ).2. |y| > 0 (i.e., y contains at least one character).3. |xy| ≤ p (i.e., the string xy has at most p characters).   Use the pumping lemma to show the following language is not regular (HINT: Use proof by contradictionto assume the language is regular and apply the pumping lemma to the language):L = {0^k1^k | k ∈ N}

A prefix of length ℓ of some word w are the first ℓ characters (in order) of w.1. Construct a context-free grammar for the language: L = {w ∈ {a, b}∗ | every prefix of w has at least as many a’s as b’s}2. Explain why every word generated by your context-free grammar (in Part 1) is contained in L. Then,prove via induction that every w ∈ L is produced by your context-free grammar.

Consider a simplified version of American football where on any possession ateam can earn 0, 3 or 7 points. What is the smallest number n0 of points such that for all n ≥ n0 and n ∈ Na team could earn n points. You must prove that your answer is correct via induction (HINT: Don’t forgetto show that n0 is the smallest number above which any number of points is reachable).

Consider a vocabulary consisting of the nucleotide bases V = {A, T, G, C}.Construct a DFA to recognize strings which end in AAGT .(a) Draw the DFA with clear markings of all states including start and acceptance state(s).(b) Simulate the DFA to show that string T GAAGT will be accepted by the DFA.(c) Simulate the DFA to show that string T AAGT G will not be accepted by the DFA.

A palindrome is a string that reads the same backward as it does forward. For example, abaaaba is a palindrome. Suppose that we need to define a language that generates palindromes.(a) Define a phase structure grammar that generates the set of all palindromes over the alphabet {a, b}clearly describing the recursive rules that generates palindromes. Use the notation Symbol → rule. Theempty set is denoted by λ. Clearly identify the terminal and non-terminal symbols in your grammar.(b) Show that the palindrome abaaaba can be recognized by your grammar. To show this, show all stepsof parsing the expression abaaaba using the rules you defined above.

A full k-ary tree is a (rooted) tree whose nodes either have exactly k children (internal nodes) or have no children (leaves). Using structural induction, formally prove that every full k-ary tree that has x internal nodes has exactly kx + 1 nodes in total. Note that for full binary trees, i.e., when k = 2, this would imply that the total number of nodes is 2x + 1.