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3 years ago

What is the determinant ? PLS RESPOND IM IN DEEP NEED

Mathematics

1 answer:

steposvetlana [31]3 years ago

7 0

<h3>Answer: 27</h3>

=======================================================

Explanation:

Check out the diagrams below. I posted two of them. Start with figure 1.

Notice how I've copied the first two columns and placed them on the right side of the matrix.

After that, I've highlighted the diagonals. The numbers in each diagonal grouping multiply together. I've used color coding to show this.

Once you find all those products, you add up the values. Figure 1 shows a result of 42. This isn't the final answer, but it helps us get there.

Figure 2 is a similar idea, but we're doing the off diagonals instead of the main diagonals. The result here is 15.

The last step is to subtract the results found in figures 1 and 2. We get 42-15 = 27 as the final answer.

You could use co-factor expansion as an alternative method. For me, I prefer this method of multiplying diagonals. Unfortunately the method only works for 3x3 matrices.

You might be interested in

A school has a goal of getting at least 2000 boxtops. They have 872 so far. They have 8 days left to get it. At least how many d

True [87]

Answer:

School needs to collect at least 144 box tops each day to meet their goal.

Step-by-step explanation:

The total requirement of box tops = 2,000

The number of box tops they have already received = 872

So, the box tops left = Total number required- Number of tops received

=2,000 - 872

= 1,128 box tops are left so far.

Number of days left = 8

So, number of minimum tops needed each day = $\frac{\textrm{Total tops required}}{\textrm{Number of days left}}$

= $\frac{1128}{8} = 141$

Hence, they need to collect at least 144 box tops each day to meet their goal.

5 0

3 years ago

More than half of the students were excited about the project. In fact, were excited. If 10 students were not

alina1380 [7]

Answer:1/2 divided by 10

Step-by-step explanation:

8 0

3 years ago

PLS HELP

Sloan [31]

Answer:

8√5 units.

Step-by-step explanation:

See the diagram in the coordinate plane attached.

A rhombus has four equal sides and to find the perimeter of the rhombus we have to measure any of the sides of the figure of the rhombus.

The coordinates of the topmost point are (-1,-1) and that of the rightmost point are (3,-3).

Therefore, side length of the rhombus will be

$\sqrt{(- 1 - 3)^{2} + (- 1 - (- 3))^{2}} = \sqrt{20} = 2\sqrt{5}$ units.

So, the perimeter of the rhombus will be (4 × 2√5) units = 8√5 units. (Answer)

The distance between two points $(x_{1},y_{1})$ and $(x_{2},y_{2})$ on a coordinate plane is given by

$\sqrt{(x_{1} - x_{2})^{2} + (y_{1} - y_{2})^{2}}$

5 0

4 years ago

Can somebody explain to me how to do this and the answers and how you got it

yaroslaw [1]

7. Easiest method is substitution. Since y=x/2, then:
2x+3(x/2)=28
8.Substituting again, we get:
3x-6x=6
-3x=6
x=-2
(-2,6)
☺☺☺☺

6 0

3 years ago

Answer the question in the picture

nekit [7.7K]

Recall the angle sum identities:

$\sin(x+y)=\sin x\cos y+\cos x\sin y$

$\cos(x+y)=\cos x\cos y-\sin x\sin y$

Now,

$\tan(x+y)=\dfrac{\sin(x+y)}{\cos(x+y)}=\dfrac{\sin x\cos y+\cos x\sin y}{\cos x\cos y-\sin x\sin y}$

Divide through numerator and denominator by $\cos x\cos y$ to get

$\tan(x+y)=\dfrac{\tan x+\tan y}{1-\tan x\tan y}$

Next, we use the fact that $x,y$ lie in the first quadrant to determine that

$\sin x=\dfrac12\implies\cos x=\sqrt{1-\sin^2x}=\dfrac{\sqrt3}2$

$\cos y=\dfrac{\sqrt2}2\implies\sin x=\sqrt{1-\cos^2x}=\dfrac1{\sqrt2}$

So we then have

$\tan x=\dfrac{\sin x}{\cos x}=\dfrac{\frac12}{\frac{\sqrt3}2}=\dfrac1{\sqrt3}$

$\tan y=\dfrac{\sin y}{\cos y}=\dfrac{\frac1{\sqrt2}}{\frac{\sqrt2}2}=1$

Finally,

$\tan(x+y)=\dfrac{\frac1{\sqrt3}+1}{1-\frac1{\sqrt3}}=\dfrac{1+\sqrt3}{\sqrt3-1}=2+\sqrt3\approx3.73$

4 0

3 years ago