All categories

4 years ago

I need help with this question plzzzzzzzz

Mathematics

1 answer:

mina [271]4 years ago

6 0

Answer:

Your answer is A.

Step-by-step explanation:

If you take the Cords of 'A' and make them both negative you will find your answer.

You might be interested in

a manufacturer has 3375 yards of material on hand. if the average dress takes 3 3/8 yards of material, how many dresses can he m

shepuryov [24]

We know that

3 3/8-------------> (3*8+3)/8-----------> 27/8 yd

if 1 dress take---------------> 27/8 yd
X-----------------------------> 3375 yd
X=3375/(27/8)---------> x=1000 dresses

the answer is
He can make 1000 dresses

7 0

3 years ago

g find the 2 components of vector b = 2i + j - 3k, one parallel to a = 3i - j and another one perpendicular to a

nika2105 [10]

Answer:

The components of $\vec{b}$ parallel and perpendicular to $\vec {a}$ are $\vec {b}_{\parallel} = \frac{3}{2}\,i-\frac{1}{2}\,j$ and $\vec b _{\perp} = \frac{1}{2}\,i+\frac{3}{2}\,j-3\,k$ , respectively.

Step-by-step explanation:

Let be $\vec b = 2\,i+j-3\,k$ and $\vec a = 3\,i-j$ , the component of $\vec b$ parallel to $\vec a$ is calculated by the following expression:

$\vec b_{\parallel} = (\vec b \bullet \hat{a}) \cdot \hat{a}$

Where $\hat{a}$ is the unit vector of $\vec a$ , dimensionless and $\bullet$ is the operator of scalar product.

The unit vector of $\vec a$ is:

$\hat{a} = \frac{\vec {a}}{\|\vec a\|}$

Where $\|\vec {a}\|$ is the norm of $\vec a$ , whose value is determined by Pythagorean Theorem.

The component of $\vec{b}$ parallel to $\vec {a}$ is:

$\|\vec {a}\| = \sqrt{3^{2}+(-1)^{2}+0^{2}}$

$\|\vec {a}\| = \sqrt{10}$

$\hat{a} = \frac{1}{\sqrt{10}} \cdot (3\,i-j)$

$\hat{a} = \frac{3}{\sqrt{10}}\,i -\frac{1}{\sqrt{10}} \,j$

$\vec{b}\bullet \hat{a} = (2)\cdot \left(\frac{3}{\sqrt{10}} \right)+(1)\cdot \left(-\frac{1}{\sqrt{10}} \right)+(-3)\cdot \left(0\right)$

$\vec b \bullet \hat{a} = \frac{5}{\sqrt{10}}$

$\vec b_{\parallel} = \frac{5}{\sqrt{10}}\cdot \left(\frac{3}{\sqrt{10}}\,i-\frac{1}{\sqrt{10}}\,j \right)$

$\vec {b}_{\parallel} = \frac{3}{2}\,i-\frac{1}{2}\,j$

Now, the component of $\vec {b}$ perpendicular to $\vec{a}$ is found by vector subtraction:

$\vec{b}_{\perp} = \vec {b}-\vec {b}_{\parallel}$

If $\vec b = 2\,i+j-3\,k$ and $\vec {b}_{\parallel} = \frac{3}{2}\,i-\frac{1}{2}\,j$ , then:

$\vec{b}_{\perp} = (2\,i+j-3\,k)-\left(\frac{3}{2}\,i-\frac{1}{2}\,j \right)$

$\vec b _{\perp} = \frac{1}{2}\,i+\frac{3}{2}\,j-3\,k$

4 0

3 years ago

What is the surface area of the outside of a cube shaped closed-top water tank whose edge length is 7.2 ft? A.373.25 B.311.04 C.

sertanlavr [38]

We know, Surface area of a Cube = 6a²

Substitute for a = 7.2

Then, SA = 6 * (7.2)²

SA = 6 * 51.84 = 311.04 Ft²

In short, Your Answer would be Option B

Hope this helps!

3 0

4 years ago

A bag contains 5 red marbles , 6 blue marbles and 4 green marbles. Susie selects a marble and returns it to the bag before selec

gogolik [260]

Whilst it seems an unlikely scenario, unless we have reason to believe Susie is not making a random choice but is making a free selection, then the previous withdrawals make no difference as the marble is returned each time. Therefore the probability is the same as at the beginning which is 5 red / 15 total marbles, or 1 in 3.

3 0

4 years ago

Laila read 36 pages in 4 hours. Which expression can be used to find the number of pages she read per hour?

MatroZZZ [7]

The last one sounds like the best one to me

3 0

3 years ago

Read 2 more answers