11. Let n be a positive integer and [r], [y e Zn. Show that the following...
Exercise 9. Let n 2 2 be a positive integer. Let a -(ri,...,^n) ER". For any a,y E R" sphere of radius 1 centered at the origin. Let x E Sn-be fixed. Let v be a random vector that is uniformly distributed in S"1. Prove: 10Vn
* (9) Let n be a positive integer. Define : Z → Zn by (k) = [k]. (a) Show that is a homomorphism. (b) Find Ker(6) and Im(). yrcises (c) To what familiar group is the quotient group Z/nZ isomorphic? Explain.
QUESTION 2 (Chapter 12, Exercises 787, p289) Let n be a positive integer. Let 1,1 E MEXa(R) satisfy the condition that Σ-laul 1 i < n. Show that Ic] < 1 for all c E spec(A). 1 for all
2. (a) Let 11 = 0 and Zn+1=2r" +1 for all n E N. In +2 i. Find 2, , and ii. Prove that (r converges and find the value of its limit (b) Let a-V2, and define @n+1 = V2+@n for all n 1. Prove that lim an exists and equals 2 Hint: For both parts try to apply the Monotone Convergence Theorem
(i) Show that R is a subring of the polynomial ring Rx. | R{]4 (ii) Let k be a fixed positive integer and be the set of all polynomials of degree less than or equal to k. Is R[xk a subring of R[a]? 2r4+3x - 5 when it is (iii) Find the quotient q(x divided by P2(x) of the polynomial P1( and remainder r(x) - 2c + 1 in - (iv) List all the polynomials of degree 3 in Z...
Let n be a positive integer, and let s and t be integers. Then
the following hold.
I need the prove for (iii)
Lemma 8.1 Let n be a positive integer, and let s and t be integers. Then the following hold. (i) We have s et mod n if and only if n dividest - s. (ii) We have pris + t) = Hn (s) +Mn(t) mod n. (iii) We have Hr(st) = Hn (3) Men(t) mod n. Proof....
subring of the polynomial ring R{z] (i Show that R is a (ii) Let k be a fixed positive integer and Rrk be the set of all polynomials of degree less than or subring of Ra (iii) Find the quotient q(x) and remainder r(x) of the polynomial P\(x) 2x in Z11] equal to k. Is Rr]k a T52r43 -5 when divided by P2(x) = iv) List all the polynomials of degree 3 in Z2[r].
subring of the polynomial ring R{z]...
(i) Vz, y E R : (z +R y) , (z) +s (y) ii )-1s (5) A ring homomorphism. (2 pts) Let m be a positive integer, and let d be a positive divisor of Show that the map a : z/mZ 2/dZ by a(a mod m) show that t has properties (i)-(ii) in the previous problem mod d is a ring homomorphism (i.e.,
1. Let m be a nonnegative integer, and n a positive integer. Using the division algorithm we can write m=qn+r, with 0 <r<n-1. As in class define (m,n) = {mc+ny: I,Y E Z} and S(..r) = {nu+ru: UV E Z}. Prove that (m,n) = S(n,r). (Remark: If we add to the definition of ged that gedan, 0) = god(0, n) = n, then this proves that ged(m, n) = ged(n,r). This result leads to a fast algorithm for computing ged(m,...
Let x, y e R" for n e N, writing x-(n, ,%), similarly for y. The Euclidean Metric of $2.2 is often called the 12 metric and written |x - y l2 for x,y e R. Show that the following three similar relations are also metrics: (a) the tancab, or 11 metric: lx-wi : = Σ Iri-Vil (b) the marirnum, or lo-metric. Ilx-ylloo:=max(zi-yil c) the comparison, or 10-metric. Ix_ylo rn (ri-Vi) where δ(t)- if t = 0