For each of the following, prove that the relation is an
equivalence relation. Then give the...
For each of the following, prove that the relation is an
equivalence relation. Then give the information about the
equivalence classes, as specified.
a) The relation ∼ on R defined by x ∼ y iff x = y or xy = 2.
Explicitly find the equivalence classes [2], [3], [−4/5 ], and
[0]
b) The relation ∼ on R+ × R+ defined by (x, y) ∼ (u, v) iff x2v
= u2y. Explicitly find the equivalence classes [(5, 2)] and...
Define the relation S on RxR by (x,y)S(a,b) if and only if x^2 +
y^2= a^2...
Define the relation S on RxR by (x,y)S(a,b) if and only if x^2 +
y^2= a^2 + b^2.
a) Prove S in an equivalence relation
b) compute [(0,0)], [(1,2)], and [(-3,4)].
c) Draw a picture in R^2 representing these three equivalence
classes.
Write vectors in R2 as (x,y). Define the relation on R2 by
writing (x1,y1) ∼ (x2,y2)...
Write vectors in R2 as (x,y). Define the relation on R2 by
writing (x1,y1) ∼ (x2,y2) iff y1 − sin x1 = y2 − sin x2 . Prove
that ∼ is an equivalence relation.
Find the classes [(0, 0)], [(2, π/2)] and draw them on the
plane. Describe the sets which are the equivalence classes for this
relation.
Consider the relation R defined on the set R as follows: ∀x, y ∈
R, (x,...
Consider the relation R defined on the set R as follows: ∀x, y ∈
R, (x, y) ∈ R if and only if x + 2 > y.
For example, (4, 3) is in R because 4 + 2 = 6, which is greater
than 3.
(a) Is the relation reflexive? Prove or disprove.
(b) Is the relation symmetric? Prove or disprove.
(c) Is the relation transitive? Prove or disprove.
(d) Is it an equivalence relation? Explain.
1. Consider the relations R = {(x,y),(y,z),(z,x)} and S =
{(y,x),(z,y),(x,z)} on {x, y, z}. a)...
1. Consider the relations R = {(x,y),(y,z),(z,x)} and S =
{(y,x),(z,y),(x,z)} on {x, y, z}. a) Explain why R is not an
equivalence relation. b) Explain why S is not an equivalence
relation. c) Find S ◦ R. d) Show that S ◦ R is an equivalence
relation. e) What are the equivalence classes of S ◦ R?
Consider the surfaces x^2 + y^2 + z^2 = 1 and (z +√2)^2 = x^2 +...
Consider the surfaces x^2 + y^2 + z^2 = 1 and (z +√2)^2 = x^2 +
y^2, and let (x0, y0, z0) be a point
in their intersection. Show that the surfaces are tangent at this
point, that is, show that they
have a common tangent plane at (x0, y0, z0).
Let S = {0,1,2,3,4,5,6,7,8}. Test the following binary relation
on S for reflexivity, symmetry, antisymmetry, and...
Let S = {0,1,2,3,4,5,6,7,8}. Test the following binary relation
on S for reflexivity, symmetry, antisymmetry, and transitivity. xρy
if and only if x+y = 8.
Is ρ an equivalence relation?
If we change the relation to x ρ y if and only if x+y 6 8 how
will the cardinality of ρ change? Give a detailed explanation.
2. draw the Hasse
diagram for the partial ordering “x divides y” on the set
{24,3,4,12,96,15,21,36}. Name any least elements, minimal elements,
greatest...
Let X = [0, 1) and Y = (0, 2).
a. Define a 1-1 function from...
Let X = [0, 1) and Y = (0, 2).
a. Define a 1-1 function from X to Y that is NOT onto Y . Prove
that it is not onto Y .
b. Define a 1-1 function from Y to X that is NOT onto X. Prove
that it is not onto X.
c. How can we use this to prove that [0, 1) ∼ (0, 2)?