Step-by-step explanation:
y = x - 4 and y = 4x + 2
=> x - 4 = 4x + 2
=> 3x = -6
=> x = -2
y = x - 4 = (-2) - 4 = -6
The solutions are x = -2 and y = -6.
The line equation is given by
where <em>m </em>is the slope and <em>b </em>is the interception with <em>Y-axis</em>
Answer:
8256
Step-by-step explanation:
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 
.
Since the two numbers vary directly, if Y is quadrupled, X will do the same. 2 times 4 is 8, 15 times 4 is 60.
X = 60.
Hope that helps!! :)
