Answer:
A), B) and D) are true
Step-by-step explanation:
A) We can prove it as follows:

B) When you compute the product Ax, the i-th component is the matrix of the i-th column of A with x, denote this by Ai x. Then, we have that
. Now, the colums of A are orthonormal so we have that (Ai x)^2=x_i^2. Then
.
C) Consider
. This set is orthogonal because
, but S is not orthonormal because the norm of (0,2) is 2≠1.
D) Let A be an orthogonal matrix in
. Then the columns of A form an orthonormal set. We have that
. To see this, note than the component
of the product
is the dot product of the i-th row of
and the jth row of
. But the i-th row of
is equal to the i-th column of
. If i≠j, this product is equal to 0 (orthogonality) and if i=j this product is equal to 1 (the columns are unit vectors), then
E) Consider S={e_1,0}. S is orthogonal but is not linearly independent, because 0∈S.
In fact, every orthogonal set in R^n without zero vectors is linearly independent. Take a orthogonal set
and suppose that there are coefficients a_i such that
. For any i, take the dot product with u_i in both sides of the equation. All product are zero except u_i·u_i=||u_i||. Then
then
.
Answer:
A and B
Step-by-step explanation:

Now, look at your answer choices, which options are less than or equal to -2?
x ≤ -2, Check your answers:
A. -3 ≤ -2?
This statement is correct (-3 is < -2)
B. -2 ≤ -2 <== our original answer
This statement is correct (-2 is = to -2)
C. -1 ≤ -2
This statement is incorrect (-1 is > -2, not ≤ -2)
D. 0 ≤ -2
This statement is incorrect (0 is > -2, not ≤ -2)
E. 1 < -2
This statement is incorrect (1 is > -2, not ≤ -2)
Therefore, the correct options are A and B
Hope this helps!
Answer: D
I’d say neither are correct because a prism looks like this...
Katie would be correct if she had lines within the L shaped area
Answer:
102? hopefully this helps
Answer:
x= 65 º
y= 25 º
Step-by-step explanation: