Answer:
Recall that a relation is an <em>equivalence relation</em> if and only if is symmetric, reflexive and transitive. In order to simplify the notation we will use A↔B when A is in relation with B.
<em>Reflexive: </em>We need to prove that A↔A. Let us write J for the identity matrix and recall that J is invertible. Notice that
. Thus, A↔A.
<em>Symmetric</em>: We need to prove that A↔B implies B↔A. As A↔B there exists an invertible matrix P such that
. In this equality we can perform a right multiplication by
and obtain
. Then, in the obtained equality we perform a left multiplication by P and get
. If we write
and
we have
. Thus, B↔A.
<em>Transitive</em>: We need to prove that A↔B and B↔C implies A↔C. From the fact A↔B we have
and from B↔C we have
. Now, if we substitute the last equality into the first one we get
.
Recall that if P and Q are invertible, then QP is invertible and
. So, if we denote R=QP we obtained that
. Hence, A↔C.
Therefore, the relation is an <em>equivalence relation</em>.
Answer:
<h3>The possibilities of length and width of the rectangle are </h3><h3>x=1, y=0.24;</h3><h3>x=0.5, y=0.48;</h3><h3>x=0.25, y=0.96;</h3><h3>x=2, y=0.12</h3>
Step-by-step explanation:
Given that the area is 0.24 square meter
The area of a rectangle is given by
square units
Let x be the length and y be the width.
Since the area is 0.24 square meter, we have the equation:
, with x and y measures in meters
If we want to know some possibilities of x and y, we can assume a value for one of them, and then calculate the other one using the equation.
Now choosing some values for "x", we have:
Put x = 1

∴ y = 0.24
Now put x = 0.5 we get
∴ y = 0.48
Put x = 0.25
∴ y = 0.96
Put x = 2

∴ y = 0.12
Answer:
x² + 2x - 5
Step-by-step explanation:
(f + g)(x) = f(x) + g(x)
f(x) + g(x)
= 2x + 3 + x² - 8 ← collect like terms
= x² + 2x - 5
A rational number is any number that can be written <em>as a ratio of two integers</em>.
0.62 fits the bill, as it can be written as the ratio 62/100 (or simplified to the ratio 31/50)