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3 years ago

I need help with this pls! 15 points!

Mathematics

1 answer:

OLga [1]3 years ago

8 0

Answer:

Step-by-step explanation:

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Find a nonzero vector orthogonal to the plane through the points: ????=(0,0,1), ????=(−2,3,4), ????=(−2,2,0).

ser-zykov [4K]

Answer:

The nonzero vector orthogonal to the plane is <-9,-8,2>.

Step-by-step explanation:

Consider the given points are P=(0,0,1), Q=(−2,3,4), R=(−2,2,0).

$\overrightarrow {PQ}==$

$\overrightarrow {PR}==$

The nonzero vector orthogonal to the plane through the points P,Q, and R is

$\overrightarrow n=\overrightarrow {PQ}\times \overrightarrow {PR}$

$\overrightarrow n=\det \begin{pmatrix}i&j&k\\ \:\:\:\:\:-2&3&3\\ \:\:\:\:\:-2&2&-1\end{pmatrix}$

Expand along row 1.

$\overrightarrow n=i\det \begin{pmatrix}3&3\\ 2&-1\end{pmatrix}-j\det \begin{pmatrix}-2&3\\ -2&-1\end{pmatrix}+k\det \begin{pmatrix}-2&3\\ -2&2\end{pmatrix}$

$\overrightarrow n=i(-9)-j(8)+k(2)$

$\overrightarrow n=-9i-8j+2k$

$\overrightarrow n=$

Therefore, the nonzero vector orthogonal to the plane is <-9,-8,2>.

8 0

3 years ago

Two students walk in the same direction along a straight path, at a constant speed - one at .90 m/s and the other at 1.90 m/s.a.

anyanavicka [17]

Answer:

a)The second student arrive 7 minutes and 36 seconds sooner

b)They have to walk 598,51 m

Step-by-step explanation:

Speed= Distance/Time

We are looking for time now

Time = Distance/Speed

First student

Time = 780 m/0.90 m/s=866,66 seconds

Second student

Time = 780 m/1.90 m/s=410,52 seconds

Difference=866,66-410,52= 456,14 seconds

In minutes

Difference= 456,14 seconds /60=7 minutes 36 seconds

Distance=Speed x Time

Speed¹ x Time¹ =Speed² x Time²

Time¹= Time² + 5.50 min

5.50 min =350 seconds

Time² =Speed¹ x Time¹ /Speed²

Time² =Speed¹ x (Time² + 350 seconds ) /Speed²

Time² =0.9 x (Time² + 350 seconds ) /1.9

Time² =0,4737 x (Time² + 350 seconds )

Time² =0,4737 Time² + 165,79 seconds

Time² - 0,4737 Time² = 165,79 seconds

0,5263 Time² = 165,79 seconds

Time² = 165,79 seconds/0,5263 =315,01 seconds

Distance=1,9 x 315,01 seconds = 598,51 m

5 0

3 years ago

1st. (2 root 2 + root 3 ) ( 2 root 3 - root 2)

satela [25.4K]

Answer:

1st: 3*root6 + 5

2nd: 35*root2 + 115

3rd: 24*root2 - 20*root6 + 15*root3 - 18

4th: 17*root6 - 38

5th: 13*root10 - 42

Step-by-step explanation:

To simplify these expressions we need to use the distributive property:

(a + b) * (c + d) = ac + ad + bc + bd

So simplifying each expression, we have:

1st.

(2 root 2 + root 3 ) ( 2 root 3 - root 2)

= 4*root6 - 2*2 + 2*3 - root6

= 3*root6 - 4 + 9

= 3*root6 + 5

2nd.

(root 5 + 2 root 10) (3 root 5 + root 10)

= 3 * 5 + root50 + 6*root50 + 2*10

= 15 + 5*root2 + 30*root2 + 100

= 35*root2 + 115

3rd.

(4 root 6 - 3 root 3) (2 root 3 - 5)

= 8*root18 - 20*root6 - 6*3 + 15root3

= 24*root2 - 20*root6 + 15*root3 - 18

4rd.

(6 root 3 - 5 root 2 ) (2 root 2 - root 3)

= 12*root6 - 6*3 - 10*2 + 5*root6

= 17*root6 - 18 - 20

= 17*root6 - 38

5th.

(root 10 - 3 ) ( 4 - 3 root 10)

= 4*root10 - 3*10 - 12 + 9*root10

= 13*root10 - 30 - 12

= 13*root10 - 42

8 0

3 years ago

Plz help<br>urgent !!!!<br>will give the brainliest !!

Mkey [24]

Answer:

$X = \begin{bmatrix}1&3\\ 2&4\end{bmatrix}$

Step-by-step explanation:

The question we have at hand is, in other words,

$\begin{bmatrix}4&2\\ \:1&1\end{bmatrix}\left(X\right)=\begin{bmatrix}8&20\\ \:3&7\end{bmatrix}$ - where we have to solve for the value of $X$

If we have to isolate $X$ here, then we would have to take the inverse of the following matrix ...

$\begin{bmatrix}4&2\\ \:1&1\end{bmatrix}$ ... so that it should be as follows ... $\begin{bmatrix}4&2\\ \:1&1\end{bmatrix}^{-1}$

Therefore, we can conclude that the equation as to solve for " $X$ " will be the following,

$X=\begin{bmatrix}4&2\\ 1&1\end{bmatrix}^{-1}\begin{bmatrix}8&20\\ 3&7\end{bmatrix}$ - First find the 2 x 2 matrix inverse of the first portion,

$\begin{bmatrix}4&2\\ 1&1\end{bmatrix}^{-1}$ = $\frac{1}{\det \begin{pmatrix}4&2\\ 1&1\end{pmatrix}}\begin{pmatrix}1&-2\\ -1&4\end{pmatrix}$ = $\frac{1}{2}\begin{bmatrix}1&-2\\ -1&4\end{bmatrix}$ = $\begin{bmatrix}\frac{1}{2}&-1\\ -\frac{1}{2}&2\end{bmatrix}$

At this point we have to multiply the rows of the first matrix by the rows of the second matrix,

$X = \begin{bmatrix}\frac{1}{2}&-1\\ -\frac{1}{2}&2\end{bmatrix}\begin{bmatrix}8&20\\ 3&7\end{bmatrix}$ ,

$X = \begin{pmatrix}\frac{1}{2}\cdot \:8+\left(-1\right)\cdot \:3&\frac{1}{2}\cdot \:20+\left(-1\right)\cdot \:7\\ \left(-\frac{1}{2}\right)\cdot \:8+2\cdot \:3&\left(-\frac{1}{2}\right)\cdot \:20+2\cdot \:7\end{pmatrix}$ - Simplifying this, we should get ...

$\begin{bmatrix}1&3\\ 2&4\end{bmatrix}$ ... which is our solution.

7 0

3 years ago

Use the law of exponents to rewrite. 4^9x4^8

sergij07 [2.7K]

Answer:

4^9+8 or 4^17

Step-by-step explanation:

3 0

3 years ago

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