Which point is an x-intercept of the quadratic function
f(x) = (x + 6)(x - 3)? THE ANSWER IS D.
Answer:440.925
Step-by-step explanation:
For this case we have the following system of equations:

Equating both equations we have:

We must find the solutions, for this we factor. We look for two numbers that, when multiplied, result in 4 and when added, result in 5. These numbers are 4 and 1:

Then, the factorized equation is of the form:

Thus, the solutions are:

We look for solutions for the variable "y":

Thus, the system solutions are given by:
ANswer:

Answer:
F(x) = 1/x^2
Step-by-step explanation:
F(x) = 1/x^2 is
y = 1/x^2
graph goes up to 10 each side
plug in 1,2,3,4,5,6,7,8,9,10 for x and see what y looks like
when x is 1,2,3,4,5,6,7,8,9,10
y is 1,1/4,1/9,etc
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
.