say R1, R2,...., Rn are
commutative rings with unity. Show that U(R1 +
R2 +.... +...
say R1, R2,...., Rn are
commutative rings with unity. Show that U(R1 +
R2 +.... + Rn) = U( R1) +
U(R2)+ .... U(Rn). Where U - is the units of
the ring.
Let R and S be commutative rings with unity. (a) Let I be an
ideal of R and let J be an ideal of S. Prove that I × J = {(a, b) |
a ∈ I, b ∈ J} is an ideal of R × S. (b) (Harder!) Let L be any
ideal of R × S. Prove that there exists an ideal I of R and an
ideal J of S such that L = I × J.
let r1 and r2 be the relations represented as r1 (ABC)
and r2 (ADE) .Assume the corresponding domains of both the tables
are same.r1 has 2000 tuples and r2 has 4500 tuples
1.common tuples between r1 and r2 are 500, what would be the
resultant number of tuples for r1-r2, justify your answer
2.assuming 500 as the common tuples between r1 and r2,what is the
maximum number of tuples that results in ]] A( r1) U ]] A r2.
justify...
A. Consider two concentric spherical structures of radius r1 and
r2 such that r1 < r2 and full load Q and -2Q respectively.
Calculate the magnitude of the field on ́ectrico in all three
regions, i.e. within the smaller sphere, between the spheres and
outside the sphere of the larger radius.
Where does the electric field point to for this system?
(no matter what material these concentric spherical are made
of)
B. Two cylindrical coaxial shells with radius r1 and...
A field is a commutative ring with
unity in which every nonzero element is a unit.
Question: Show that Z_5 under
addition and multiplication mod 5 is a field. (state the
operations, identities, inverses)
Suppose R1,R2,...,Rn are mutually independent and uniformly
distributed random variables on [0,1]. Assume R(1) ≤ R(2) ≤···≤
R(n) are the order statistics of the R1,R2,...,Rn. It is given that
1 ≤ a < b ≤ n. What is the distribution of R(b)−R(a)?
Two hoops have the same mass M. Their radii are
R1 and R2 = 2
R1. Similarly, two uniform disks also have mass
M and the radii, R1 and
R2. Which of these objects has the largest
moment of inertia about the axis perpendicular to the screen and
through the center of the hoop or disk? The moment of inertia of a
uniform disk of mass mand radius r about its
center is (1/2)mr2; for a hoop it is
mr2....
Consider the following relations:
R1 = {(a, b) ∈
R2 ∣ a > b}, the
greater than relation
R2 = {(a, b) ∈
R2 ∣ a ≥ b}, the
greater than or equal to relation
R3 = {(a, b) ∈
R2 ∣ a < b}, the
less than relation
R4 = {(a, b) ∈
R2 ∣ a ≤ b}, the less
than or equal to relation
R5 = {(a, b) ∈
R2 ∣ a = b}, the
equal to relation...