

7. (i) Suppose that 28 = 0 and y12 = 0. What is the least natural...
13. (i) For each of the following equations, find all the natural numbers n that satisfy it (a) φ(n)-4 (b) o(n) 6 (c) ф(n) 8 (d) φ(n) = 10 (ii) Prove or disprove: (a) For every natural number k, there are only finitely many natural num- bers n such that ф(n)-k (b) For every integer n > 2, there are at least two distinction integers that are invertible modulo n (c) For every integers a, b,n with n > 1...
(a) Suppose that f is continuous on [0, 1] and f(o) = f(1). Let n be 20. any natural number. Prove that there is some number x such that f fx+1/m), as shown in Figure 16 for n 4. Hint: Consider the function g(x) = f(x)-f(x + 1/n); what would be true if g(x)ヂ0 for all x? "(b) Suppose 0 < a 1, but that a is not equal to 1/n for any natural number n. Find a function f...
6. Suppose X and Y have the joint pdf fr,y) = 2 exp(-:- 0 ) 0< <y otherwise o a. Find Px.x, the correlation coefficient between X and Y. b. Let U = 2X-1 and V=Y +2. What is pu.v, the correlation coefficient between U and V? c. Repeat (b) if U = -TX and V = Y + In 2. d. Let W = Y - X. Compute Var (W). e. Refer to (d). Find an interval that will...
Problem 5 (a) Let A be an n × m matrix, and suppose that there exists a m × n matrix B such that BA = 1- (i) Let b є Rn be such that the system of equations Ax b has at least one solution. Prove that this solution must be unique. (ii) Must it be the case that the system of equations Ax = b has a solution for every b? Prove or provide a counterexample. (b) Let...
Problem 7. Fix a natural number n € N, and let en denote the equivalence relation "modulo n" on Z defined by x =n y if and only if n|y-r. axun (a) (6 points) Prove that pe N is prime, and if a, b € Z with a? Ep 62, then either a = b or a =p -b. (b) (4 points) Provide a counterexample showing the result in (a) may fail when p is not prime. That is, find...
Suppose I want to prove that a property P holds for every natural number Quasion 9 Not yot arewaed Pi holds for every natural number i amaler than k, then PA) holds Now I show that every natural number k, Points but at This means that P hoids for every natural number F Fag gesson Select one True Falso Queion 10 Suppose I want to prove that a property Pholds for avery nonnegadve intogor. Now I show that for every...
7. Suppose X and Y have joint pdf f(x,y) = 24x y if x >0, y>0,x+y<1 and 0 otherwise. Find P(Y > 2x).
1 (0) Suposo = ( ).*-[0–, ]md = [ i ] Pad z and such that 27-+= . (4) Suppose ū= W = | and W = . Find x and y such that 2ū–37+5W = 7. 6 – Y (5) Justify your answers: (i) Is a linear combination of mbination of 1 ] and [ : 12 and | 1 [ 3 47 0 ? (ii) Is 2 a linear combination of -1 and | 1 0
10. A natural number n is called attainable if there exists non-negative integers a and b such that n - 5a + 8b. Otherwise, n is called unattainable. Construct an 9 x 6 matrix whose rows are indexed by the integers between 0 and 8 and whose columns are indexed by the integers between 0 and 5 whose (x, y)-th entry equals 5x + 8y for any 0 < r < 8 and (a) Mark down all the attainable numbers...
Question 8: For any integer n 20 and any real number x with 0<<1, define the function (Using the ratio test from calculus, it can be shown that this infinite series converges for any fixed integer n.) Determine a closed form expression for Fo(x). (You may use any result that was proven in class.) Let n 21 be an integer and let r be a real number with 0<< 1. Prove that 'n-1(2), n where 1 denotes the derivative of...