Chapter 3.8, Problem 13P

Q/solved by d'Alembert:- utt =uxx u (X10) = f(x) u + (×10) = 0

Let U = = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} be the universal set. Use the following subsets of U to determine if each statement is true or false. A = {0, 1, 3, 5} and B = {2, 3, 4, 5,9} • true AUB = {3,5} • true A - B = {0, 1} ⚫ true B = {0, 1, 6, 7, 8, 10} ⚫ true An Bc • true (AUB) = {0,1} = {0, 1, 2, 4, 6, 7, 8, 9, 10} ⚫ true A x B = {(0,2), (1, 3), (3, 4), (5,5)}

Let A = {x Z | x=0 (mod 6)} and B = {x = Z | x = 0 (mod 9)}. Which of the following sentences describes the set relationship between A and B ? *Keep in mind that Ç means proper subset. AÇ B BÇA A = B AnB = 0 none of these

Let U = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} be the universal set. Let A = {0, 1, 2, 3, 9} and B = {2, 3, 4, 5, 6}. Select all elements in An B. 2 3 4 5 18 7 8 9 ☐ 10

Let U = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10} be the universal set. Let A = {0, 1, 2, 3, 9} and B = {2, 3, 4, 5, 6}. Select all elements in An B. 1 2 ✓ 3 + 5 10 7 > 00 ☐ 10

Complete the missing components of the know-show table to prove the statement be- low. Alternatively, you may construct your own table to prove the statement using the strategy that comes to your mind. Statement: For all integers n, if n is odd, then n³ + 4n+5 is even. Step Know P P1 n³ is odd P2 P3 5 is odd 0 Step Reason Hypothesis Product of even and odd is even 5 = 2(2)+1 Show Reason

Consider the following false statement: For all integers a and b, if ab = 1 (mod 8), then a = 1 (mod 8) or b = 1 (mod 8). (a) Which of the following could be used as a counterexample. Select all that apply. a = -7 and b = −7 a = 1 and b = 23 ☐ a = 3 and b: = −5 ☐ a = 4 and b = 6 □ a = −1 and b = −9

1. Given X' = X 3 e2t (a) Verify that X₁(t) = (e) and X2(t) = (et) - are solutions to the given system. (b) Verify that X₁(t) and X2(t) form a fundamental set on the interval (-∞, ∞). (c) Write the general solution to the given system. (d) Find the solution that satisfies the initial condition X(0) = ( 2 ).

Prove that a relation X defined on a set A that is reflexive, symmetric and antisymmetric is an equivalence relation and determine the equivalence classes.