We define a relation ∼ on R^2 by (x1,y1)∼(x2,y2) if and only if
(y2−y1) ∈ 2Z. Show that the relation∼is an equivalence relation and
describe the equivalence class of the point (0,1).
1. Let ρ: R2 ×R2 →R be given by ρ((x1,y1),(x2,y2)) = |x1
−x2|+|y1 −y2|.
(a) Prove that (R2,ρ) is a metric space.
(b) In (R2,ρ), sketch the open ball with center (0,0) and radius
1. 2. Let {xn} be a sequence in a metric space (X,ρ). Prove that if
xn → a and xn → b for some a,b ∈ X, then a = b.
3. (Optional) Let (C[a,b],ρ) be the metric space discussed in
example 10.6 on page 344...
The parametric equations
x = x1 +
(x2 −
x1)t, y
= y1 +
(y2 −
y1)t
where
0 ≤ t ≤ 1
describe the line segment that joins the points
P1(x1,
y1)
and
P2(x2,
y2).
Use a graphing device to draw the triangle with vertices
A(1, 1), B(4, 3), C(1, 6). Find the
parametrization, including endpoints, and sketch to check. (Enter
your answers as a comma-separated list of equations. Let x
and y be in terms of t.)
Show that the set ℝ2R2, equipped with operations
(?1,?1)+˜(?2,?2)=(?1+?2+1,?1+?2−1)(x1,y1)+~(x2,y2)=(x1+x2+1,y1+y2−1)
? ⋅˜ (?,?)=(??+?−1,??−?+1)
(1)defines a vector space over ℝR.
(2)Show that the vector space ?V defined in question 1 is
isomorphic to ℝ2R2 equipped with its usual vector space operations.
This means you need to define an invertible linear map
?:?→ℝ2T:V→R2.
Determine whether the set with the definition of addition of
vectors and scalar multiplication is a vector space. If it is,
demonstrate algebraically that it satisfies the 8 vector axioms. If
it's not, identify and show algebraically every axioms which is
violated. Assume the usual addition and scalar multiplication if
it's not identified. V = R^2 , < X1 , X2 > + < Y1 , Y2
> = < X1 + Y1 , 0> c< X1 , X2 >...
Determine whether the set with the definition of addition of
vectors and scalar multiplication is a vector space. If it is,
demonstrate algebraically that it satisfies the 8 vector axioms. If
it's not, identify and show algebraically every axioms which is
violated. Assume the usual addition and scalar multiplication if
it's not defined. V = { (x1, x2, x3) ∈ R^3 | x1 > or equal to 0,
x2 > or equal to 0, x3 > or equal to 0}
Determine whether the set with the definition of addition of
vectors and scalar multiplication is a vector space. If it is,
demonstrate algebraically that it satisfies the 8 vector axioms. If
it's not, identify and show algebraically every axioms which is
violated. Assume the usual addition and scalar multiplication if
it's not defined. V = { f : R --> R | f(1) = 0 }
Determine whether the set with the definition of addition of
vectors and scalar multiplication is a vector space. If it is,
demonstrate algebraically that it satisfies the 8 vector axioms. If
it's not, identify and show algebraically every axioms which is
violated. Assume the usual addition and scalar multiplication if
it's not defined. V = {all polynomials with real coefficients with
degree > or equal to 3 and the zero polynomial}
Let X1, X2, X3 be independent having N(0,1). Let Y1=(X1-X2)/√2,
Y2=(X1+X2-2*X3)/√6, Y3=(X1+X2+X3)/√3. Find the joint pdf of Y1, Y2,
Y3, and the marginal pdfs.
Let X1,X2,X3 be i.i.d. N(0,1) random variables. Suppose Y1 = X1
+ X2 + X3, Y2 = X1 −X2, Y3 =X1 −X3. Find the joint pdf of Y =
(Y1,Y2,Y3)′ using : Multivariate normal distribution
properties.