How do you rotate the coordinate (9,-6) 270 degrees counterclockwise?

In-s [12.5K]

ANSWER

24

EXPLANATION

For a matrix A of order n×n, the cofactor $C_{ij}$ of element $a_{ij}$ is defined to be

$C_{ij} = (-1)^{i+j} M_{ij}$

$M_{ij}$ is the minor of element $a_{ij}$ equal to the determinant of the matrix we get by taking matrix A and deleting row i and column j.

Here, we have

$C_{11} = (-1)^{1+1} M_{11} = M_{11}$

M₁₁ is the determinant of the matrix that is matrix A with row 1 and column 1 removed. The bold entries are the row and the column we delete.

$\begin{aligned} A=\begin{bmatrix} \bf 1 & \bf -6 & \bf -4\\ \bf 7 & 0 & -3 \\ \bf -9 & 8 & -8 \end{bmatrix} \implies M_{11} &= \text{det}\left(\begin{bmatrix} 0&-3 \\ 8&-8 \end{bmatrix} \right) \end{aligned}$

Since the determinant of a 2×2 matrix is

$\det\left( \begin{bmatrix} a & b \\ c& d \end{bmatrix} \right) = ad-bc$

it follows that

$\begin{aligned} A=\begin{bmatrix} \bf 1 & \bf -6 & \bf -4\\ \bf 7 & 0 & -3 \\ \bf -9 & 8 & -8 \end{bmatrix} \implies M_{11} &= \text{det}\left(\begin{bmatrix} 0&-3 \\ 8&-8 \end{bmatrix} \right) \\ &= (0)(-8) - (-3)(8) \\ &= -(-24) \\ &= 24 \end{aligned}$

so $C_{11} = M_{11} = 24$

4 0

3 years ago

Plz help i only need this question who ever get its right will get 77 point

Ivanshal [37]

Answer:

I don't know..............

8 0

2 years ago

Read 2 more answers

The daily parking garage at BWI Airport charges $3.00 per hour for the first two hours, and $2.00 per hour for the third, fourth

Law Incorporation [45]

Answer:

b would be the awnser

Step-by-step explanation:

im guessing

7 0

2 years ago

Solve for x 9x + 1 equals 25 + x edg 2020? x=2 x=3 x=4 x=5

gregori [183]

No no no no no no no no no no no no

3 0

2 years ago

Each month cameron budgets $1040 for fixed expenses $980 for living expenses and $120 for annual expenses his annual net income

sineoko [7]

Let us first find how much he is spending every year, to do this let's find his monthly expense and multiply it by 12.

Every month Cameron spends 1040 + 980 + 120 = 2140

To find out how much he spends yearly, multiply the monthly value by 12,
2140 x 12 = 25680

This value is more than his net income so he clearly has a surplus, but to check we can subtract 129 from every month to get:

(1040 + 980 + 120 - 129) = 2011

2011 x 12 = 24132, which shows that his budget is saving 129 surplus every month. Choice B is correct.

5 0

3 years ago

Read 2 more answers